Номер 35.6, страница 249 - гдз по физике 10-11 класс задачник Гельфгат, Генденштейн
Авторы: Гельфгат И. М., Генденштейн Л. Э., Кирик Л. А.
Тип: Задачник
Издательство: Илекса
Год издания: 2008 - 2026
Уровень обучения: профильный
Цвет обложки: красный лупа, парень едет на велосипеде
ISBN: 978-5-89237-252-7
Популярные ГДЗ в 10 классе
Электродинамика. Электромагнитные колебания и волны. 35. Волновые свойства света. Упражнения - номер 35.6, страница 249.
App\Models\Task {#1030 // resources/views/models/task/default.blade.php #connection: "mysql" #table: "tasks" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:24 [ "id" => 1319797 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "249" "field_page_end" => "250" "field_url" => "/10-klass/fizika/gelfgat-zadachnik/35-6" "field_display_title" => "35.6" "field_outside_task" => "0" "field_task_type" => Illuminate\Database\Eloquent\Collection {#1037 #items: array:1 [ 0 => App\Models\Term {#1036 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 26 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "номер" "field_cases" => array:6 [ "field_accusative_case" => "номер" "field_creative_case" => "номером" "field_dative_case" => "номеру" "field_genitive_case" => "номера" "field_nominative_case" => "номер" "field_prepositional_case" => "номере" ] "field_short_name" => "№" ] #original: array:6 [ "id" => 26 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "номер" "field_cases" => array:6 [ "field_accusative_case" => "номер" "field_creative_case" => "номером" "field_dative_case" => "номеру" "field_genitive_case" => "номера" "field_nominative_case" => "номер" "field_prepositional_case" => "номере" ] "field_short_name" => "№" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_match" => null "breadcrumbs" => [] "edition_groups" => Illuminate\Database\Eloquent\Collection {#1035 #items: [] #escapeWhenCastingToString: false } "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1074 #items: array:1 [ 0 => App\Models\Branch {#1034 #connection: "mysql" #table: "branches" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:24 [ "id" => 1319339 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Электродинамика" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1039 #items: [] #escapeWhenCastingToString: false } "field_page_start" => "163" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1038 #items: array:1 [ 0 => App\Models\Book {#1040 #connection: "mysql" #table: "books" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:50 [ "id" => 5400 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_tree_default_status" => "tasks" "field_pages_status" => null "field_subject" => Illuminate\Database\Eloquent\Collection {#1041 #items: array:1 [ 0 => App\Models\Term {#1042 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:10 [ …10] #original: array:10 [ …10] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] …8 } ] #escapeWhenCastingToString: false } "field_class" => Illuminate\Database\Eloquent\Collection {#1043 #items: array:2 [ 0 => App\Models\Term {#1044 …30} 1 => App\Models\Term {#1045 …30} ] #escapeWhenCastingToString: false } "field_publisher" => Illuminate\Database\Eloquent\Collection {#1046 #items: array:1 [ 0 => App\Models\Term {#1047 …30} ] #escapeWhenCastingToString: false } "field_author" => Illuminate\Database\Eloquent\Collection {#1048 #items: array:3 [ 0 => App\Models\Term {#1049 …30} 1 => App\Models\Term {#1050 …30} 2 => App\Models\Term {#1051 …30} ] #escapeWhenCastingToString: false } "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1052 #items: [] #escapeWhenCastingToString: false } "field_book_type" => Illuminate\Database\Eloquent\Collection {#1053 #items: array:1 [ 0 => App\Models\Term {#1054 …30} ] #escapeWhenCastingToString: false } "field_country" => Illuminate\Database\Eloquent\Collection {#1055 #items: array:1 [ 0 => App\Models\Term {#1056 …30} ] #escapeWhenCastingToString: false } "field_city" => Illuminate\Database\Eloquent\Collection {#1057 #items: array:1 [ 0 => App\Models\Term {#1058 …30} ] #escapeWhenCastingToString: false } "field_series" => Illuminate\Database\Eloquent\Collection {#1059 #items: [] #escapeWhenCastingToString: false } "field_umk" => Illuminate\Database\Eloquent\Collection {#1060 #items: [] #escapeWhenCastingToString: false } "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1061 #items: array:1 [ 0 => App\Models\Term {#1062 …30} ] #escapeWhenCastingToString: false } "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1063 #items: [] #escapeWhenCastingToString: false } "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1064 #items: [] #escapeWhenCastingToString: false } "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1065 #items: [] #escapeWhenCastingToString: false } "field_under_the_edition_degree" => null "field_cover_description" => "лупа, парень едет на велосипеде" "field_publication_year" => "2008" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебное издание" "field_allowed" => null "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "459" "field_priority" => null "field_default_folder" => "/fizika_10/gelfgat-z/" "field_isbn" => "978-5-89237-252-7" "field_cover" => array:1 [ 0 => "/media/fizika_10/gelfgat-z/covers/cover1.webp?ts=1756049816" ] "field_cover_alts" => array:1 [ 0 => "" ] "field_covers" => array:1 [ 0 => array:4 [ "path" => "/media/fizika_10/gelfgat-z/covers/cover1.webp?ts=1756049816" "alt" => "" "width" => "1566" "height" => "2412" ] ] "field_popular_book" => "0" "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1066 #items: [] #escapeWhenCastingToString: false } "field_new_book" => Illuminate\Database\Eloquent\Collection {#1067 #items: [] #escapeWhenCastingToString: false } "field_old_book" => Illuminate\Database\Eloquent\Collection {#1068 #items: [] #escapeWhenCastingToString: false } "field_url" => "/10-klass/fizika/gelfgat-zadachnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1069 #items: array:1 [ 0 => App\Models\Term {#1070 …30} ] #escapeWhenCastingToString: false } "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "breadcrumbs" => array:3 [ "class" => 381 "subject" => 556 "class_subject" => 494 ] ] #original: array:50 [ "id" => 5400 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_tree_default_status" => "tasks" "field_pages_status" => null "field_subject" => Illuminate\Database\Eloquent\Collection {#1041} "field_class" => Illuminate\Database\Eloquent\Collection {#1043} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1046} "field_author" => Illuminate\Database\Eloquent\Collection {#1048} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1052} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1053} "field_country" => Illuminate\Database\Eloquent\Collection {#1055} "field_city" => Illuminate\Database\Eloquent\Collection {#1057} "field_series" => Illuminate\Database\Eloquent\Collection {#1059} "field_umk" => Illuminate\Database\Eloquent\Collection {#1060} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1061} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1063} "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1064} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1065} "field_under_the_edition_degree" => null "field_cover_description" => "лупа, парень едет на велосипеде" "field_publication_year" => "2008" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебное издание" "field_allowed" => null "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "459" "field_priority" => null "field_default_folder" => "/fizika_10/gelfgat-z/" "field_isbn" => "978-5-89237-252-7" "field_cover" => array:1 [ 0 => "/media/fizika_10/gelfgat-z/covers/cover1.webp?ts=1756049816" ] "field_cover_alts" => array:1 [ 0 => "" ] "field_covers" => array:1 [ 0 => array:4 [ "path" => "/media/fizika_10/gelfgat-z/covers/cover1.webp?ts=1756049816" "alt" => "" "width" => "1566" "height" => "2412" ] ] "field_popular_book" => "0" "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1066} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1067} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1068} "field_url" => "/10-klass/fizika/gelfgat-zadachnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1069} "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "breadcrumbs" => array:3 [ "class" => 381 "subject" => 556 "class_subject" => 494 ] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "branch_parent" => Illuminate\Database\Eloquent\Collection {#1071 #items: [] #escapeWhenCastingToString: false } ] #original: array:24 [ "id" => 1319339 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Электродинамика" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1039} "field_page_start" => "163" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1038} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1071} ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "parent_branches" => Illuminate\Database\Eloquent\Collection {#1110 #items: array:4 [ 0 => App\Models\Branch {#1120 #connection: "mysql" #table: "branches" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:24 [ "id" => 1319339 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Электродинамика" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1121 #items: [] #escapeWhenCastingToString: false } "field_page_start" => "163" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1155 #items: array:1 [ 0 => App\Models\Book {#1122 #connection: "mysql" #table: "books" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:50 [ "id" => 5400 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_tree_default_status" => "tasks" "field_pages_status" => null "field_subject" => Illuminate\Database\Eloquent\Collection {#1124 #items: array:1 [ 0 => App\Models\Term {#1123 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:10 [ "id" => 6493 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Физика" "field_abbreviated_name" => null "field_cases" => array:6 [ "field_accusative_case" => "физику" "field_creative_case" => "физикой" "field_dative_case" => "физике" "field_genitive_case" => "физики" "field_nominative_case" => "физика" "field_prepositional_case" => "физике" ] "field_foreign_lang_name" => null "field_short_name" => null "field_subject_type" => "technical_subject" "field_translit" => "fizika" ] #original: array:10 [ "id" => 6493 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Физика" "field_abbreviated_name" => null "field_cases" => array:6 [ "field_accusative_case" => "физику" "field_creative_case" => "физикой" "field_dative_case" => "физике" "field_genitive_case" => "физики" "field_nominative_case" => "физика" "field_prepositional_case" => "физике" ] "field_foreign_lang_name" => null "field_short_name" => null "field_subject_type" => "technical_subject" "field_translit" => "fizika" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_class" => Illuminate\Database\Eloquent\Collection {#1125 #items: array:2 [ 0 => App\Models\Term {#1126 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 5459 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "10" "field_cases" => array:6 [ "field_accusative_case" => "десятый" "field_creative_case" => "десятым" "field_dative_case" => "десятому" "field_genitive_case" => "десятого" "field_nominative_case" => "десятый" "field_prepositional_case" => "десятом" ] "field_translit" => "desjatyj" ] #original: array:6 [ "id" => 5459 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "10" "field_cases" => array:6 [ "field_accusative_case" => "десятый" "field_creative_case" => "десятым" "field_dative_case" => "десятому" "field_genitive_case" => "десятого" "field_nominative_case" => "десятый" "field_prepositional_case" => "десятом" ] "field_translit" => "desjatyj" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 1 => App\Models\Term {#1127 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 5460 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "11" "field_cases" => array:6 [ "field_accusative_case" => "одиннадцатый" "field_creative_case" => "одиннадцатым" "field_dative_case" => "одиннадцатому" "field_genitive_case" => "одинадцатого" "field_nominative_case" => "одинадцатый" "field_prepositional_case" => "одиннадцатом" ] "field_translit" => "odinadcatyj" ] #original: array:6 [ "id" => 5460 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "11" "field_cases" => array:6 [ "field_accusative_case" => "одиннадцатый" "field_creative_case" => "одиннадцатым" "field_dative_case" => "одиннадцатому" "field_genitive_case" => "одинадцатого" "field_nominative_case" => "одинадцатый" "field_prepositional_case" => "одиннадцатом" ] "field_translit" => "odinadcatyj" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_publisher" => Illuminate\Database\Eloquent\Collection {#1128 #items: array:1 [ 0 => App\Models\Term {#1129 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 5158 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Илекса" "field_cases" => null "field_translit" => "ileksa" ] #original: array:6 [ "id" => 5158 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Илекса" "field_cases" => null "field_translit" => "ileksa" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_author" => Illuminate\Database\Eloquent\Collection {#1130 #items: array:3 [ 0 => App\Models\Term {#1131 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:12 [ "id" => 4102 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Гельфгат" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Илья" "field_patronymic" => "Маркович" "field_surname_rp" => null ] #original: array:12 [ "id" => 4102 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Гельфгат" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Илья" "field_patronymic" => "Маркович" "field_surname_rp" => null ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 1 => App\Models\Term {#1132 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:12 [ "id" => 4104 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Генденштейн" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Лев" "field_patronymic" => "Элевич" "field_surname_rp" => "Генденштейна" ] #original: array:12 [ "id" => 4104 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Генденштейн" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Лев" "field_patronymic" => "Элевич" "field_surname_rp" => "Генденштейна" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 2 => App\Models\Term {#1133 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:12 [ "id" => 4583 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Кирик" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Леонид" "field_patronymic" => "Анатольевич" "field_surname_rp" => null ] #original: array:12 [ "id" => 4583 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Кирик" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Леонид" "field_patronymic" => "Анатольевич" "field_surname_rp" => null ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1134 #items: [] #escapeWhenCastingToString: false } "field_book_type" => Illuminate\Database\Eloquent\Collection {#1135 #items: array:1 [ 0 => App\Models\Term {#1136 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:10 [ "id" => 6518 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Задачник" "field_book_type_foreign" => null "field_cases" => array:6 [ "field_accusative_case" => "задачник" "field_creative_case" => "задачником" "field_dative_case" => "задачнику" "field_genitive_case" => "задачника" "field_nominative_case" => "задачник" "field_prepositional_case" => "задачнике" ] "field_plural_form" => null "field_short_name" => null "field_short_name_foreign" => null "field_translit" => "zadachnik" ] #original: array:10 [ "id" => 6518 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Задачник" "field_book_type_foreign" => null "field_cases" => array:6 [ "field_accusative_case" => "задачник" "field_creative_case" => "задачником" "field_dative_case" => "задачнику" "field_genitive_case" => "задачника" "field_nominative_case" => "задачник" "field_prepositional_case" => "задачнике" ] "field_plural_form" => null "field_short_name" => null "field_short_name_foreign" => null "field_translit" => "zadachnik" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_country" => Illuminate\Database\Eloquent\Collection {#1137 #items: array:1 [ 0 => App\Models\Term {#1138 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 9 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Россия" "field_cases" => array:6 [ "field_accusative_case" => null "field_creative_case" => null "field_dative_case" => null "field_genitive_case" => null "field_nominative_case" => null "field_prepositional_case" => null ] "field_translit" => "rossiya" ] #original: array:6 [ "id" => 9 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Россия" "field_cases" => array:6 [ "field_accusative_case" => null "field_creative_case" => null "field_dative_case" => null "field_genitive_case" => null "field_nominative_case" => null "field_prepositional_case" => null ] "field_translit" => "rossiya" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_city" => Illuminate\Database\Eloquent\Collection {#1139 #items: array:1 [ 0 => App\Models\Term {#1140 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 15 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Москва" "field_cases" => array:6 [ "field_accusative_case" => null "field_creative_case" => null "field_dative_case" => null "field_genitive_case" => null "field_nominative_case" => null "field_prepositional_case" => null ] "field_translit" => "moskva" ] #original: array:6 [ "id" => 15 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Москва" "field_cases" => array:6 [ "field_accusative_case" => null "field_creative_case" => null "field_dative_case" => null "field_genitive_case" => null "field_nominative_case" => null "field_prepositional_case" => null ] "field_translit" => "moskva" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_series" => Illuminate\Database\Eloquent\Collection {#1141 #items: [] #escapeWhenCastingToString: false } "field_umk" => Illuminate\Database\Eloquent\Collection {#1142 #items: [] #escapeWhenCastingToString: false } "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1143 #items: array:1 [ 0 => App\Models\Term {#1144 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 40 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "профильный" "field_cases" => array:6 [ "field_accusative_case" => "профильный" "field_creative_case" => "профильным" "field_dative_case" => "профильному" "field_genitive_case" => "профильного" "field_nominative_case" => "профильный" "field_prepositional_case" => "профильном" ] "field_translit" => "profilnyy" ] #original: array:6 [ "id" => 40 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "профильный" "field_cases" => array:6 [ "field_accusative_case" => "профильный" "field_creative_case" => "профильным" "field_dative_case" => "профильному" "field_genitive_case" => "профильного" "field_nominative_case" => "профильный" "field_prepositional_case" => "профильном" ] "field_translit" => "profilnyy" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1145 #items: [] #escapeWhenCastingToString: false } "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1146 #items: [] #escapeWhenCastingToString: false } "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1147 #items: [] #escapeWhenCastingToString: false } "field_under_the_edition_degree" => null "field_cover_description" => "лупа, парень едет на велосипеде" "field_publication_year" => "2008" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебное издание" "field_allowed" => null "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "459" "field_priority" => null "field_default_folder" => "/fizika_10/gelfgat-z/" "field_isbn" => "978-5-89237-252-7" "field_cover" => array:1 [ 0 => "/media/fizika_10/gelfgat-z/covers/cover1.webp?ts=1756049816" ] "field_cover_alts" => array:1 [ 0 => "" ] "field_covers" => array:1 [ 0 => array:4 [ "path" => "/media/fizika_10/gelfgat-z/covers/cover1.webp?ts=1756049816" "alt" => "" "width" => "1566" "height" => "2412" ] ] "field_popular_book" => "0" "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1148 #items: [] #escapeWhenCastingToString: false } "field_new_book" => Illuminate\Database\Eloquent\Collection {#1149 #items: [] #escapeWhenCastingToString: false } "field_old_book" => Illuminate\Database\Eloquent\Collection {#1150 #items: [] #escapeWhenCastingToString: false } "field_url" => "/10-klass/fizika/gelfgat-zadachnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1151 #items: array:1 [ 0 => App\Models\Term {#1152 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 46 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "красный" "field_cases" => array:6 [ "field_accusative_case" => "красный" "field_creative_case" => "красным" "field_dative_case" => "красному" "field_genitive_case" => "красного" "field_nominative_case" => "красный" "field_prepositional_case" => "красном" ] "field_translit" => "krasnyy" ] #original: array:6 [ "id" => 46 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "красный" "field_cases" => array:6 [ "field_accusative_case" => "красный" "field_creative_case" => "красным" "field_dative_case" => "красному" "field_genitive_case" => "красного" "field_nominative_case" => "красный" "field_prepositional_case" => "красном" ] "field_translit" => "krasnyy" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "breadcrumbs" => array:3 [ "class" => 381 "subject" => 556 "class_subject" => 494 ] ] #original: array:50 [ "id" => 5400 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_tree_default_status" => "tasks" "field_pages_status" => null "field_subject" => Illuminate\Database\Eloquent\Collection {#1124} "field_class" => Illuminate\Database\Eloquent\Collection {#1125} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1128} "field_author" => Illuminate\Database\Eloquent\Collection {#1130} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1134} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1135} "field_country" => Illuminate\Database\Eloquent\Collection {#1137} "field_city" => Illuminate\Database\Eloquent\Collection {#1139} "field_series" => Illuminate\Database\Eloquent\Collection {#1141} "field_umk" => Illuminate\Database\Eloquent\Collection {#1142} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1143} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1145} "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1146} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1147} "field_under_the_edition_degree" => null "field_cover_description" => "лупа, парень едет на велосипеде" "field_publication_year" => "2008" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебное издание" "field_allowed" => null "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "459" "field_priority" => null "field_default_folder" => "/fizika_10/gelfgat-z/" "field_isbn" => "978-5-89237-252-7" "field_cover" => array:1 [ 0 => "/media/fizika_10/gelfgat-z/covers/cover1.webp?ts=1756049816" ] "field_cover_alts" => array:1 [ 0 => "" ] "field_covers" => array:1 [ 0 => array:4 [ "path" => "/media/fizika_10/gelfgat-z/covers/cover1.webp?ts=1756049816" "alt" => "" "width" => "1566" "height" => "2412" ] ] "field_popular_book" => "0" "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1148} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1149} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1150} "field_url" => "/10-klass/fizika/gelfgat-zadachnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1151} "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "breadcrumbs" => array:3 [ "class" => 381 "subject" => 556 "class_subject" => 494 ] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "branch_parent" => Illuminate\Database\Eloquent\Collection {#1153 #items: [] #escapeWhenCastingToString: false } ] #original: array:24 [ "id" => 1319339 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Электродинамика" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1121} "field_page_start" => "163" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1155} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1153} ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 1 => App\Models\Branch {#1154 #connection: "mysql" #table: "branches" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:24 [ "id" => 1319371 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Электромагнитные колебания и волны" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1156 #items: [] #escapeWhenCastingToString: false } "field_page_start" => "241" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1157 #items: array:1 [ 0 => App\Models\Book {#1122} ] #escapeWhenCastingToString: false } "branch_parent" => Illuminate\Database\Eloquent\Collection {#1158 #items: array:1 [ 0 => App\Models\Branch {#1034} ] #escapeWhenCastingToString: false } ] #original: array:24 [ "id" => 1319371 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Электромагнитные колебания и волны" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1156} "field_page_start" => "241" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1157} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1158} ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 2 => App\Models\Branch {#1159 #connection: "mysql" #table: "branches" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:24 [ "id" => 1319376 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "35. Волновые свойства света" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1160 #items: [] #escapeWhenCastingToString: false } "field_page_start" => "247" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1161 #items: array:1 [ 0 => App\Models\Book {#1122} ] #escapeWhenCastingToString: false } "branch_parent" => Illuminate\Database\Eloquent\Collection {#1170 #items: array:1 [ 0 => App\Models\Branch {#1169 #connection: "mysql" #table: "branches" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:24 [ "id" => 1319371 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Электромагнитные колебания и волны" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1171 #items: [] #escapeWhenCastingToString: false } "field_page_start" => "241" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1172 #items: array:1 [ 0 => App\Models\Book {#1122} ] #escapeWhenCastingToString: false } "branch_parent" => Illuminate\Database\Eloquent\Collection {#1173 #items: array:1 [ 0 => App\Models\Branch {#1034} ] #escapeWhenCastingToString: false } ] #original: array:24 [ "id" => 1319371 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Электромагнитные колебания и волны" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1171} "field_page_start" => "241" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1172} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1173} ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } ] #original: array:24 [ "id" => 1319376 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "35. Волновые свойства света" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1160} "field_page_start" => "247" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1161} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1170} ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 3 => App\Models\Branch {#1163 #connection: "mysql" #table: "branches" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:24 [ "id" => 1319377 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Упражнения" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1162 #items: [] #escapeWhenCastingToString: false } "field_page_start" => "247" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1166 #items: array:1 [ 0 => App\Models\Book {#1122} ] #escapeWhenCastingToString: false } "branch_parent" => Illuminate\Database\Eloquent\Collection {#1179 #items: array:1 [ 0 => App\Models\Branch {#1178 #connection: "mysql" #table: "branches" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:24 [ "id" => 1319376 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "35. Волновые свойства света" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1180 #items: [] #escapeWhenCastingToString: false } "field_page_start" => "247" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1181 #items: array:1 [ 0 => App\Models\Book {#1122} ] #escapeWhenCastingToString: false } "branch_parent" => Illuminate\Database\Eloquent\Collection {#1182 #items: array:1 [ 0 => App\Models\Branch {#1169} ] #escapeWhenCastingToString: false } ] #original: array:24 [ "id" => 1319376 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "35. Волновые свойства света" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1180} "field_page_start" => "247" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1181} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1182} ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } ] #original: array:24 [ "id" => 1319377 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Упражнения" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1162} "field_page_start" => "247" "field_branch_display" => "0" "field_branch_expanded" => "0" "field_display_branch_in_title" => "1" "field_display_task_interval" => "0" "field_display_branch_page" => "1" "field_branch_title_in_content" => "0" "field_navigation_title" => null "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1166} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1179} ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "content" => Illuminate\Database\Eloquent\Collection {#1072 #items: array:2 [ 0 => App\Models\Element {#1101 #connection: "mysql" #table: "elements" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:7 [ "id" => 1493945 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1091 #items: array:1 [ 0 => App\Models\Edition {#1100 #connection: "mysql" #table: "editions" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:21 [ "id" => 5430 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Условие" "field_order" => "1" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1097 #items: array:1 [ 0 => App\Models\Term {#1099 …30} ] #escapeWhenCastingToString: false } "field_content_type" => "free" "field_content_mode" => "text, image" "field_page_content_mode" => "image" "field_content_text_checked" => null "field_page_content_text_checked" => "0" "field_solution_author" => "Автор" "field_moderator" => "stas" "field_edition_type" => "statement" "field_root_dir" => "0-" "field_responsible" => Illuminate\Database\Eloquent\Collection {#1098 #items: [] #escapeWhenCastingToString: false } "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1096 #items: [] #escapeWhenCastingToString: false } "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1095 #items: [] #escapeWhenCastingToString: false } "field_content_source" => null ] #original: array:21 [ "id" => 5430 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Условие" "field_order" => "1" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1097} "field_content_type" => "free" "field_content_mode" => "text, image" "field_page_content_mode" => "image" "field_content_text_checked" => null "field_page_content_text_checked" => "0" "field_solution_author" => "Автор" "field_moderator" => "stas" "field_edition_type" => "statement" "field_root_dir" => "0-" "field_responsible" => Illuminate\Database\Eloquent\Collection {#1098} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1096} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1095} "field_content_source" => null ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "task" => array:2 [ "refs" => "1319797" "type" => "task" ] "text" => "<p><strong>35.6.</strong> Точечный источник $\text{A}$ монохроматического света с длиной волны $\lambda = 500 \text{ нм}$ расположен на расстоянии $l = 50 \text{ см}$ от экрана, а на расстоянии $1.5l$ от экрана находится параллельное экрану плоское зеркало (см. рисунок после текста задачи). Какой вид имеет интерференционная картина на экране? Темная или светлая интерференционная полоса проходит на расстоянии $R = 2 \text{ мм}$ от точки $\text{O}$ (см. рисунок)?</p><p><strong><em>Решение.</em></strong> Интерференционную картину на экране можно рассматривать как результат сложения световых волн от источника $\text{A}$ и его изображения $A_1$ в зеркале (см. рисунок; $A_1O = 2l$).</p><p>Следует учесть, что из-за «потери» полуволны при отражении света от зеркала источники $\text{A}$ и $A_1$ — противофазные. Интерференционная картина должна быть симметричной относительно прямой $AA_1$, поэтому на экране будут чередующиеся темные и светлые кольца с центром в точке $\text{O}$. Для произвольной точки $\text{M}$ экрана оптическая разность хода двух световых волн</p><p>$\Delta d = \frac{\lambda}{2} + A_1 M - AM = \frac{\lambda}{2} + \sqrt{4l^2 + r^2} - \sqrt{l^2 + r^2} = l + \frac{r^2}{4l}$</p><p>(мы воспользовались малостью $\text{r}$ по сравнению с $\text{l}$). Расчет показывает, что при $r = R$ разность хода $\Delta d$ составляет нечетное число полуволн. Следовательно, на расстоянии $\text{R}$ от точки $\text{O}$ находится середина темной полосы. Фактически этот результат получен в предположении, что приведенное значение $\text{l}$ является точным.</p>" "img" => array:2 [ 0 => array:5 [ "name" => "6-1.jpg" "alt" => null "width" => "1394" "height" => 357 "path" => "/media/fizika_10/gelfgat-z/0-35/6-1.webp?ts=1756251143" ] 1 => array:5 [ "name" => "6-2.jpg" "alt" => null "width" => "1358" "height" => 2233 "path" => "/media/fizika_10/gelfgat-z/0-35/6-2.webp?ts=1756251143" ] ] ] #original: array:7 [ "id" => 1493945 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1091} "task" => array:2 [ "refs" => "1319797" "type" => "task" ] "text" => "<p><strong>35.6.</strong> Точечный источник $\text{A}$ монохроматического света с длиной волны $\lambda = 500 \text{ нм}$ расположен на расстоянии $l = 50 \text{ см}$ от экрана, а на расстоянии $1.5l$ от экрана находится параллельное экрану плоское зеркало (см. рисунок после текста задачи). Какой вид имеет интерференционная картина на экране? Темная или светлая интерференционная полоса проходит на расстоянии $R = 2 \text{ мм}$ от точки $\text{O}$ (см. рисунок)?</p><p><strong><em>Решение.</em></strong> Интерференционную картину на экране можно рассматривать как результат сложения световых волн от источника $\text{A}$ и его изображения $A_1$ в зеркале (см. рисунок; $A_1O = 2l$).</p><p>Следует учесть, что из-за «потери» полуволны при отражении света от зеркала источники $\text{A}$ и $A_1$ — противофазные. Интерференционная картина должна быть симметричной относительно прямой $AA_1$, поэтому на экране будут чередующиеся темные и светлые кольца с центром в точке $\text{O}$. Для произвольной точки $\text{M}$ экрана оптическая разность хода двух световых волн</p><p>$\Delta d = \frac{\lambda}{2} + A_1 M - AM = \frac{\lambda}{2} + \sqrt{4l^2 + r^2} - \sqrt{l^2 + r^2} = l + \frac{r^2}{4l}$</p><p>(мы воспользовались малостью $\text{r}$ по сравнению с $\text{l}$). Расчет показывает, что при $r = R$ разность хода $\Delta d$ составляет нечетное число полуволн. Следовательно, на расстоянии $\text{R}$ от точки $\text{O}$ находится середина темной полосы. Фактически этот результат получен в предположении, что приведенное значение $\text{l}$ является точным.</p>" "img" => array:2 [ 0 => array:5 [ "name" => "6-1.jpg" "alt" => null "width" => "1394" "height" => 357 "path" => "/media/fizika_10/gelfgat-z/0-35/6-1.webp?ts=1756251143" ] 1 => array:5 [ "name" => "6-2.jpg" "alt" => null "width" => "1358" "height" => 2233 "path" => "/media/fizika_10/gelfgat-z/0-35/6-2.webp?ts=1756251143" ] ] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 1 => App\Models\Element {#1093 #connection: "mysql" #table: "elements" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 1691502 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1085 #items: array:1 [ 0 => App\Models\Edition {#1094 #connection: "mysql" #table: "editions" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:21 [ "id" => 6138 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Решение" "field_order" => "2" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1089 #items: array:1 [ 0 => App\Models\Term {#1092 …30} ] #escapeWhenCastingToString: false } "field_content_type" => "free" "field_content_mode" => "text" "field_page_content_mode" => "" "field_content_text_checked" => null "field_page_content_text_checked" => "0" "field_solution_author" => "Gemini 2.5 Pro" "field_moderator" => "tolik" "field_edition_type" => "solution" "field_root_dir" => "1-" "field_responsible" => Illuminate\Database\Eloquent\Collection {#1090 #items: [] #escapeWhenCastingToString: false } "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1088 #items: [] #escapeWhenCastingToString: false } "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1084 #items: [] #escapeWhenCastingToString: false } "field_content_source" => null ] #original: array:21 [ "id" => 6138 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Решение" "field_order" => "2" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1089} "field_content_type" => "free" "field_content_mode" => "text" "field_page_content_mode" => "" "field_content_text_checked" => null "field_page_content_text_checked" => "0" "field_solution_author" => "Gemini 2.5 Pro" "field_moderator" => "tolik" "field_edition_type" => "solution" "field_root_dir" => "1-" "field_responsible" => Illuminate\Database\Eloquent\Collection {#1090} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1088} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1084} "field_content_source" => null ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "task" => array:2 [ "refs" => "1319797" "type" => "task" ] "text" => "<p><strong>Какой вид имеет интерференционная картина на экране?</strong></p><p>Интерференционная картина на экране образуется в результате сложения волн от реального источника света A и его мнимого изображения A₁ в плоском зеркале. Эти два источника когерентны. Так как мнимое изображение A₁ и реальный источник A находятся на прямой, перпендикулярной экрану, интерференционная картина будет иметь осевую симметрию. Она будет представлять собой систему чередующихся светлых и темных концентрических колец с центром в точке O, которая является проекцией прямой A₁A на экран.</p><p><strong>Ответ:</strong> Интерференционная картина на экране представляет собой систему чередующихся светлых и темных концентрических колец с центром в точке O.</p><p><strong>Темная или светлая интерференционная полоса проходит на расстоянии R = 2 мм от точки O (см. рисунок)?</strong></p><p><strong>Дано:</strong><br>Длина волны, $ \lambda = 500 $ нм<br>Расстояние от источника до экрана, $ l = 50 $ см<br>Радиус кольца, $ R = 2 $ мм</p><p>$ \lambda = 500 \cdot 10^{-9} $ м<br>$ l = 50 \cdot 10^{-2} = 0.5 $ м<br>$ R = 2 \cdot 10^{-3} $ м</p><p><strong>Найти:</strong><br>Тип интерференционной полосы (темная или светлая) на расстоянии R.</p><p><strong>Решение:</strong></p><p>Интерференционная картина создается двумя когерентными источниками: реальным источником A и его мнимым изображением A₁ в зеркале. Расстояние от источника A до экрана равно $l$. Зеркало находится на расстоянии $1.5l$ от экрана, следовательно, расстояние от источника A до зеркала составляет $1.5l - l = 0.5l$. Мнимое изображение A₁ находится на таком же расстоянии за зеркалом, то есть на расстоянии $0.5l$ от него. Таким образом, расстояние от мнимого источника A₁ до экрана составляет $1.5l + 0.5l = 2l$.</p><p>При отражении света от оптически более плотной среды (зеркала) фаза волны меняется на $ \pi $, что эквивалентно дополнительной разности хода в $ \lambda/2 $.</p><p>Рассмотрим точку M на экране на расстоянии $R$ от центра O. Оптическая разность хода $ \Delta $ для лучей, приходящих в эту точку от источников A₁ и A, равна:</p><p>$ \Delta = (A_1M - AM) + \frac{\lambda}{2} $</p><p>где $A_1M$ и $AM$ — расстояния от источников до точки M. По теореме Пифагора:</p><p>$ A_1M = \sqrt{(2l)^2 + R^2} $<br>$ AM = \sqrt{l^2 + R^2} $</p><p>Таким образом, разность хода:</p><p>$ \Delta = \sqrt{4l^2 + R^2} - \sqrt{l^2 + R^2} + \frac{\lambda}{2} $</p><p>Поскольку $ R \ll l $ ($2 \cdot 10^{-3} \text{ м} \ll 0.5 \text{ м}$), можно использовать приближенную формулу $ \sqrt{a^2 + x^2} \approx a + \frac{x^2}{2a} $:</p><p>$ \sqrt{4l^2 + R^2} = 2l\sqrt{1 + \frac{R^2}{4l^2}} \approx 2l(1 + \frac{R^2}{8l^2}) = 2l + \frac{R^2}{4l} $<br>$ \sqrt{l^2 + R^2} = l\sqrt{1 + \frac{R^2}{l^2}} \approx l(1 + \frac{R^2}{2l^2}) = l + \frac{R^2}{2l} $</p><p>Подставим эти выражения в формулу для разности хода:</p><p>$ \Delta \approx (2l + \frac{R^2}{4l}) - (l + \frac{R^2}{2l}) + \frac{\lambda}{2} = l - \frac{R^2}{4l} + \frac{\lambda}{2} $</p><p>Условие минимума (темной полосы): $ \Delta = (m + \frac{1}{2})\lambda $, где m — целое число.<br>Условие максимума (светлой полосы): $ \Delta = m\lambda $, где m — целое число.</p><p>Найдем, какому числу длин волн кратна разность хода. Сначала проверим, является ли величина $l$ кратной целому числу длин волн:</p><p>$ \frac{l}{\lambda} = \frac{0.5}{500 \cdot 10^{-9}} = \frac{0.5}{5 \cdot 10^{-7}} = 0.1 \cdot 10^7 = 10^6 $</p><p>Так как $l$ кратно целому числу длин волн ($l = 10^6\lambda$), то в центре экрана (при R=0) разность хода $ \Delta_0 = l + \lambda/2 = (10^6 + 0.5)\lambda $, что соответствует условию минимума. В центре находится темное пятно.</p><p>Теперь найдем поправку к разности хода для точки на расстоянии R:</p><p>$ \frac{R^2}{4l} = \frac{(2 \cdot 10^{-3})^2}{4 \cdot 0.5} = \frac{4 \cdot 10^{-6}}{2} = 2 \cdot 10^{-6} $ м</p><p>Выразим эту величину в длинах волн:</p><p>$ \frac{R^2}{4l\lambda} = \frac{2 \cdot 10^{-6}}{500 \cdot 10^{-9}} = \frac{2 \cdot 10^{-6}}{5 \cdot 10^{-7}} = \frac{20}{5} = 4 $</p><p>Таким образом, $ \frac{R^2}{4l} = 4\lambda $.</p><p>Теперь мы можем найти полную оптическую разность хода в точке M:</p><p>$ \Delta = l - 4\lambda + \frac{\lambda}{2} = 10^6\lambda - 4\lambda + 0.5\lambda = (1000000 - 4 + 0.5)\lambda = 999996.5\lambda $</p><p>Полученное значение имеет вид $ (m + \frac{1}{2})\lambda $, где $m = 999996$. Это условие интерференционного минимума.</p><p><strong>Ответ:</strong> На расстоянии R = 2 мм от точки O проходит темная интерференционная полоса.</p>" ] #original: array:6 [ "id" => 1691502 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1085} "task" => array:2 [ "refs" => "1319797" "type" => "task" ] "text" => "<p><strong>Какой вид имеет интерференционная картина на экране?</strong></p><p>Интерференционная картина на экране образуется в результате сложения волн от реального источника света A и его мнимого изображения A₁ в плоском зеркале. Эти два источника когерентны. Так как мнимое изображение A₁ и реальный источник A находятся на прямой, перпендикулярной экрану, интерференционная картина будет иметь осевую симметрию. Она будет представлять собой систему чередующихся светлых и темных концентрических колец с центром в точке O, которая является проекцией прямой A₁A на экран.</p><p><strong>Ответ:</strong> Интерференционная картина на экране представляет собой систему чередующихся светлых и темных концентрических колец с центром в точке O.</p><p><strong>Темная или светлая интерференционная полоса проходит на расстоянии R = 2 мм от точки O (см. рисунок)?</strong></p><p><strong>Дано:</strong><br>Длина волны, $ \lambda = 500 $ нм<br>Расстояние от источника до экрана, $ l = 50 $ см<br>Радиус кольца, $ R = 2 $ мм</p><p>$ \lambda = 500 \cdot 10^{-9} $ м<br>$ l = 50 \cdot 10^{-2} = 0.5 $ м<br>$ R = 2 \cdot 10^{-3} $ м</p><p><strong>Найти:</strong><br>Тип интерференционной полосы (темная или светлая) на расстоянии R.</p><p><strong>Решение:</strong></p><p>Интерференционная картина создается двумя когерентными источниками: реальным источником A и его мнимым изображением A₁ в зеркале. Расстояние от источника A до экрана равно $l$. Зеркало находится на расстоянии $1.5l$ от экрана, следовательно, расстояние от источника A до зеркала составляет $1.5l - l = 0.5l$. Мнимое изображение A₁ находится на таком же расстоянии за зеркалом, то есть на расстоянии $0.5l$ от него. Таким образом, расстояние от мнимого источника A₁ до экрана составляет $1.5l + 0.5l = 2l$.</p><p>При отражении света от оптически более плотной среды (зеркала) фаза волны меняется на $ \pi $, что эквивалентно дополнительной разности хода в $ \lambda/2 $.</p><p>Рассмотрим точку M на экране на расстоянии $R$ от центра O. Оптическая разность хода $ \Delta $ для лучей, приходящих в эту точку от источников A₁ и A, равна:</p><p>$ \Delta = (A_1M - AM) + \frac{\lambda}{2} $</p><p>где $A_1M$ и $AM$ — расстояния от источников до точки M. По теореме Пифагора:</p><p>$ A_1M = \sqrt{(2l)^2 + R^2} $<br>$ AM = \sqrt{l^2 + R^2} $</p><p>Таким образом, разность хода:</p><p>$ \Delta = \sqrt{4l^2 + R^2} - \sqrt{l^2 + R^2} + \frac{\lambda}{2} $</p><p>Поскольку $ R \ll l $ ($2 \cdot 10^{-3} \text{ м} \ll 0.5 \text{ м}$), можно использовать приближенную формулу $ \sqrt{a^2 + x^2} \approx a + \frac{x^2}{2a} $:</p><p>$ \sqrt{4l^2 + R^2} = 2l\sqrt{1 + \frac{R^2}{4l^2}} \approx 2l(1 + \frac{R^2}{8l^2}) = 2l + \frac{R^2}{4l} $<br>$ \sqrt{l^2 + R^2} = l\sqrt{1 + \frac{R^2}{l^2}} \approx l(1 + \frac{R^2}{2l^2}) = l + \frac{R^2}{2l} $</p><p>Подставим эти выражения в формулу для разности хода:</p><p>$ \Delta \approx (2l + \frac{R^2}{4l}) - (l + \frac{R^2}{2l}) + \frac{\lambda}{2} = l - \frac{R^2}{4l} + \frac{\lambda}{2} $</p><p>Условие минимума (темной полосы): $ \Delta = (m + \frac{1}{2})\lambda $, где m — целое число.<br>Условие максимума (светлой полосы): $ \Delta = m\lambda $, где m — целое число.</p><p>Найдем, какому числу длин волн кратна разность хода. Сначала проверим, является ли величина $l$ кратной целому числу длин волн:</p><p>$ \frac{l}{\lambda} = \frac{0.5}{500 \cdot 10^{-9}} = \frac{0.5}{5 \cdot 10^{-7}} = 0.1 \cdot 10^7 = 10^6 $</p><p>Так как $l$ кратно целому числу длин волн ($l = 10^6\lambda$), то в центре экрана (при R=0) разность хода $ \Delta_0 = l + \lambda/2 = (10^6 + 0.5)\lambda $, что соответствует условию минимума. В центре находится темное пятно.</p><p>Теперь найдем поправку к разности хода для точки на расстоянии R:</p><p>$ \frac{R^2}{4l} = \frac{(2 \cdot 10^{-3})^2}{4 \cdot 0.5} = \frac{4 \cdot 10^{-6}}{2} = 2 \cdot 10^{-6} $ м</p><p>Выразим эту величину в длинах волн:</p><p>$ \frac{R^2}{4l\lambda} = \frac{2 \cdot 10^{-6}}{500 \cdot 10^{-9}} = \frac{2 \cdot 10^{-6}}{5 \cdot 10^{-7}} = \frac{20}{5} = 4 $</p><p>Таким образом, $ \frac{R^2}{4l} = 4\lambda $.</p><p>Теперь мы можем найти полную оптическую разность хода в точке M:</p><p>$ \Delta = l - 4\lambda + \frac{\lambda}{2} = 10^6\lambda - 4\lambda + 0.5\lambda = (1000000 - 4 + 0.5)\lambda = 999996.5\lambda $</p><p>Полученное значение имеет вид $ (m + \frac{1}{2})\lambda $, где $m = 999996$. Это условие интерференционного минимума.</p><p><strong>Ответ:</strong> На расстоянии R = 2 мм от точки O проходит темная интерференционная полоса.</p>" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "next" => array:2 [ "refs" => "1319798" "type" => "task" ] "previous" => array:2 [ "refs" => "1319796" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1104 #items: array:1 [ 0 => App\Models\Book {#1122} ] #escapeWhenCastingToString: false } "page" => Illuminate\Database\Eloquent\Collection {#1076 #items: array:1 [ 0 => App\Models\BookPage {#1106 #connection: "mysql" #table: "book_pages" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:21 [ "id" => 1341210 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "249" "field_url" => "/10-klass/fizika/gelfgat-zadachnik/page-249" "field_display_title" => "249" "field_folder" => "1" "field_image_name" => "249" "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1087 #items: [] #escapeWhenCastingToString: false } "field_weight" => "0" "field_book_parent" => Illuminate\Database\Eloquent\Collection {#1086 #items: array:1 [ 0 => App\Models\Book {#1122} ] #escapeWhenCastingToString: false } "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "edition_groups" => Illuminate\Database\Eloquent\Collection {#1082 #items: [] #escapeWhenCastingToString: false } "content" => Illuminate\Database\Eloquent\Collection {#1116 #items: array:1 [ 0 => App\Models\Element {#1108 #connection: "mysql" #table: "elements" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 1519755 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1115 #items: array:1 [ 0 => App\Models\Edition {#1100} ] #escapeWhenCastingToString: false } "book_page" => array:2 [ "refs" => "1341210" "type" => "book_page" ] "img" => array:1 [ 0 => array:5 [ "name" => "249-1.jpg" "alt" => null "width" => "1541" "height" => 2430 "path" => "/media/fizika_10/gelfgat-z/0-1/249-1.webp?ts=1756642404" ] ] ] #original: array:6 [ "id" => 1519755 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1115} "book_page" => array:2 [ "refs" => "1341210" "type" => "book_page" ] "img" => array:1 [ 0 => array:5 [ "name" => "249-1.jpg" "alt" => null "width" => "1541" "height" => 2430 "path" => "/media/fizika_10/gelfgat-z/0-1/249-1.webp?ts=1756642404" ] ] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "next" => array:2 [ "refs" => "1341211" "type" => "book_page" ] "previous" => array:2 [ "refs" => "1341209" "type" => "book_page" ] "tasks" => Illuminate\Database\Eloquent\Collection {#1281 #items: array:2 [ 0 => App\Models\Task {#1289 #connection: "mysql" #table: "tasks" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:24 [ "id" => 1319796 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "248" "field_page_end" => "249" "field_url" => "/10-klass/fizika/gelfgat-zadachnik/35-5" "field_display_title" => "35.5" "field_outside_task" => "0" "field_task_type" => Illuminate\Database\Eloquent\Collection {#1290 #items: array:1 [ 0 => App\Models\Term {#1036} ] #escapeWhenCastingToString: false } "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_match" => null "breadcrumbs" => [] "edition_groups" => Illuminate\Database\Eloquent\Collection {#1291 #items: [] #escapeWhenCastingToString: false } "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1292 #items: array:1 [ 0 => App\Models\Branch {#1120} ] #escapeWhenCastingToString: false } "parent_branches" => Illuminate\Database\Eloquent\Collection {#1293 #items: array:4 [ 0 => App\Models\Branch {#1120} 1 => App\Models\Branch {#1154} 2 => App\Models\Branch {#1159} 3 => App\Models\Branch {#1163} ] #escapeWhenCastingToString: false } "content" => Illuminate\Database\Eloquent\Collection {#1295 #items: array:2 [ 0 => App\Models\Element {#1304 …30} 1 => App\Models\Element {#1306 …30} ] #escapeWhenCastingToString: false } "next" => array:2 [ "refs" => "1319797" "type" => "task" ] "previous" => array:2 [ "refs" => "1319795" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1301 #items: array:1 [ 0 => App\Models\Book {#1122} ] #escapeWhenCastingToString: false } "page" => array:2 [ "refs" => "1341209" "type" => "book_page" ] ] #original: array:24 [ "id" => 1319796 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "248" "field_page_end" => "249" "field_url" => "/10-klass/fizika/gelfgat-zadachnik/35-5" "field_display_title" => "35.5" "field_outside_task" => "0" "field_task_type" => Illuminate\Database\Eloquent\Collection {#1290} "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_match" => null "breadcrumbs" => [] "edition_groups" => Illuminate\Database\Eloquent\Collection {#1291} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1292} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1293} "content" => Illuminate\Database\Eloquent\Collection {#1295} "next" => array:2 [ "refs" => "1319797" "type" => "task" ] "previous" => array:2 [ "refs" => "1319795" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1301} "page" => array:2 [ "refs" => "1341209" "type" => "book_page" ] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 1 => App\Models\Task {#1296 #connection: "mysql" #table: "tasks" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:24 [ "id" => 1319797 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "249" "field_page_end" => "250" "field_url" => "/10-klass/fizika/gelfgat-zadachnik/35-6" "field_display_title" => "35.6" "field_outside_task" => "0" "field_task_type" => Illuminate\Database\Eloquent\Collection {#1294 #items: array:1 [ 0 => App\Models\Term {#1036} ] #escapeWhenCastingToString: false } "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_match" => null "breadcrumbs" => [] "edition_groups" => Illuminate\Database\Eloquent\Collection {#1303 #items: [] #escapeWhenCastingToString: false } "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1299 #items: array:1 [ 0 => App\Models\Branch {#1120} ] #escapeWhenCastingToString: false } "parent_branches" => Illuminate\Database\Eloquent\Collection {#1297 #items: array:4 [ 0 => App\Models\Branch {#1120} 1 => App\Models\Branch {#1154} 2 => App\Models\Branch {#1159} 3 => App\Models\Branch {#1163} ] #escapeWhenCastingToString: false } "content" => Illuminate\Database\Eloquent\Collection {#1300 #items: array:2 [ 0 => App\Models\Element {#1101} 1 => App\Models\Element {#1093} ] #escapeWhenCastingToString: false } "next" => array:2 [ "refs" => "1319798" "type" => "task" ] "previous" => array:2 [ "refs" => "1319796" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1298 #items: array:1 [ 0 => App\Models\Book {#1122} ] #escapeWhenCastingToString: false } "page" => array:2 [ "refs" => "1341210" "type" => "book_page" ] ] #original: array:24 [ "id" => 1319797 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "249" "field_page_end" => "250" "field_url" => "/10-klass/fizika/gelfgat-zadachnik/35-6" "field_display_title" => "35.6" "field_outside_task" => "0" "field_task_type" => Illuminate\Database\Eloquent\Collection {#1294} "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_match" => null "breadcrumbs" => [] "edition_groups" => Illuminate\Database\Eloquent\Collection {#1303} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1299} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1297} "content" => Illuminate\Database\Eloquent\Collection {#1300} "next" => array:2 [ "refs" => "1319798" "type" => "task" ] "previous" => array:2 [ "refs" => "1319796" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1298} "page" => array:2 [ "refs" => "1341210" "type" => "book_page" ] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } ] #original: array:21 [ "id" => 1341210 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "249" "field_url" => "/10-klass/fizika/gelfgat-zadachnik/page-249" "field_display_title" => "249" "field_folder" => "1" "field_image_name" => "249" "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1087} "field_weight" => "0" "field_book_parent" => Illuminate\Database\Eloquent\Collection {#1086} "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "edition_groups" => Illuminate\Database\Eloquent\Collection {#1082} "content" => Illuminate\Database\Eloquent\Collection {#1116} "next" => array:2 [ "refs" => "1341211" "type" => "book_page" ] "previous" => array:2 [ "refs" => "1341209" "type" => "book_page" ] "tasks" => Illuminate\Database\Eloquent\Collection {#1281} ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } ] #original: array:24 [ "id" => 1319797 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "249" "field_page_end" => "250" "field_url" => "/10-klass/fizika/gelfgat-zadachnik/35-6" "field_display_title" => "35.6" "field_outside_task" => "0" "field_task_type" => Illuminate\Database\Eloquent\Collection {#1037} "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "field_match" => null "breadcrumbs" => [] "edition_groups" => Illuminate\Database\Eloquent\Collection {#1035} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1074} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1110} "content" => Illuminate\Database\Eloquent\Collection {#1072} "next" => array:2 [ "refs" => "1319798" "type" => "task" ] "previous" => array:2 [ "refs" => "1319796" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1104} "page" => array:2 [ "refs" => "1341210" "type" => "book_page" ] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] }
№35.6 (с. 249)
Условие. №35.6 (с. 249)
скриншот условия
35.6. Точечный источник $\text{A}$ монохроматического света с длиной волны $\lambda = 500 \text{ нм}$ расположен на расстоянии $l = 50 \text{ см}$ от экрана, а на расстоянии $1.5l$ от экрана находится параллельное экрану плоское зеркало (см. рисунок после текста задачи). Какой вид имеет интерференционная картина на экране? Темная или светлая интерференционная полоса проходит на расстоянии $R = 2 \text{ мм}$ от точки $\text{O}$ (см. рисунок)?
Решение. Интерференционную картину на экране можно рассматривать как результат сложения световых волн от источника $\text{A}$ и его изображения $A_1$ в зеркале (см. рисунок; $A_1O = 2l$).
Следует учесть, что из-за «потери» полуволны при отражении света от зеркала источники $\text{A}$ и $A_1$ — противофазные. Интерференционная картина должна быть симметричной относительно прямой $AA_1$, поэтому на экране будут чередующиеся темные и светлые кольца с центром в точке $\text{O}$. Для произвольной точки $\text{M}$ экрана оптическая разность хода двух световых волн
$\Delta d = \frac{\lambda}{2} + A_1 M - AM = \frac{\lambda}{2} + \sqrt{4l^2 + r^2} - \sqrt{l^2 + r^2} = l + \frac{r^2}{4l}$
(мы воспользовались малостью $\text{r}$ по сравнению с $\text{l}$). Расчет показывает, что при $r = R$ разность хода $\Delta d$ составляет нечетное число полуволн. Следовательно, на расстоянии $\text{R}$ от точки $\text{O}$ находится середина темной полосы. Фактически этот результат получен в предположении, что приведенное значение $\text{l}$ является точным.
Решение. №35.6 (с. 249)
Какой вид имеет интерференционная картина на экране?
Интерференционная картина на экране образуется в результате сложения волн от реального источника света A и его мнимого изображения A₁ в плоском зеркале. Эти два источника когерентны. Так как мнимое изображение A₁ и реальный источник A находятся на прямой, перпендикулярной экрану, интерференционная картина будет иметь осевую симметрию. Она будет представлять собой систему чередующихся светлых и темных концентрических колец с центром в точке O, которая является проекцией прямой A₁A на экран.
Ответ: Интерференционная картина на экране представляет собой систему чередующихся светлых и темных концентрических колец с центром в точке O.
Темная или светлая интерференционная полоса проходит на расстоянии R = 2 мм от точки O (см. рисунок)?
Дано:
Длина волны, $ \lambda = 500 $ нм
Расстояние от источника до экрана, $ l = 50 $ см
Радиус кольца, $ R = 2 $ мм
$ \lambda = 500 \cdot 10^{-9} $ м
$ l = 50 \cdot 10^{-2} = 0.5 $ м
$ R = 2 \cdot 10^{-3} $ м
Найти:
Тип интерференционной полосы (темная или светлая) на расстоянии R.
Решение:
Интерференционная картина создается двумя когерентными источниками: реальным источником A и его мнимым изображением A₁ в зеркале. Расстояние от источника A до экрана равно $l$. Зеркало находится на расстоянии $1.5l$ от экрана, следовательно, расстояние от источника A до зеркала составляет $1.5l - l = 0.5l$. Мнимое изображение A₁ находится на таком же расстоянии за зеркалом, то есть на расстоянии $0.5l$ от него. Таким образом, расстояние от мнимого источника A₁ до экрана составляет $1.5l + 0.5l = 2l$.
При отражении света от оптически более плотной среды (зеркала) фаза волны меняется на $ \pi $, что эквивалентно дополнительной разности хода в $ \lambda/2 $.
Рассмотрим точку M на экране на расстоянии $R$ от центра O. Оптическая разность хода $ \Delta $ для лучей, приходящих в эту точку от источников A₁ и A, равна:
$ \Delta = (A_1M - AM) + \frac{\lambda}{2} $
где $A_1M$ и $AM$ — расстояния от источников до точки M. По теореме Пифагора:
$ A_1M = \sqrt{(2l)^2 + R^2} $
$ AM = \sqrt{l^2 + R^2} $
Таким образом, разность хода:
$ \Delta = \sqrt{4l^2 + R^2} - \sqrt{l^2 + R^2} + \frac{\lambda}{2} $
Поскольку $ R \ll l $ ($2 \cdot 10^{-3} \text{ м} \ll 0.5 \text{ м}$), можно использовать приближенную формулу $ \sqrt{a^2 + x^2} \approx a + \frac{x^2}{2a} $:
$ \sqrt{4l^2 + R^2} = 2l\sqrt{1 + \frac{R^2}{4l^2}} \approx 2l(1 + \frac{R^2}{8l^2}) = 2l + \frac{R^2}{4l} $
$ \sqrt{l^2 + R^2} = l\sqrt{1 + \frac{R^2}{l^2}} \approx l(1 + \frac{R^2}{2l^2}) = l + \frac{R^2}{2l} $
Подставим эти выражения в формулу для разности хода:
$ \Delta \approx (2l + \frac{R^2}{4l}) - (l + \frac{R^2}{2l}) + \frac{\lambda}{2} = l - \frac{R^2}{4l} + \frac{\lambda}{2} $
Условие минимума (темной полосы): $ \Delta = (m + \frac{1}{2})\lambda $, где m — целое число.
Условие максимума (светлой полосы): $ \Delta = m\lambda $, где m — целое число.
Найдем, какому числу длин волн кратна разность хода. Сначала проверим, является ли величина $l$ кратной целому числу длин волн:
$ \frac{l}{\lambda} = \frac{0.5}{500 \cdot 10^{-9}} = \frac{0.5}{5 \cdot 10^{-7}} = 0.1 \cdot 10^7 = 10^6 $
Так как $l$ кратно целому числу длин волн ($l = 10^6\lambda$), то в центре экрана (при R=0) разность хода $ \Delta_0 = l + \lambda/2 = (10^6 + 0.5)\lambda $, что соответствует условию минимума. В центре находится темное пятно.
Теперь найдем поправку к разности хода для точки на расстоянии R:
$ \frac{R^2}{4l} = \frac{(2 \cdot 10^{-3})^2}{4 \cdot 0.5} = \frac{4 \cdot 10^{-6}}{2} = 2 \cdot 10^{-6} $ м
Выразим эту величину в длинах волн:
$ \frac{R^2}{4l\lambda} = \frac{2 \cdot 10^{-6}}{500 \cdot 10^{-9}} = \frac{2 \cdot 10^{-6}}{5 \cdot 10^{-7}} = \frac{20}{5} = 4 $
Таким образом, $ \frac{R^2}{4l} = 4\lambda $.
Теперь мы можем найти полную оптическую разность хода в точке M:
$ \Delta = l - 4\lambda + \frac{\lambda}{2} = 10^6\lambda - 4\lambda + 0.5\lambda = (1000000 - 4 + 0.5)\lambda = 999996.5\lambda $
Полученное значение имеет вид $ (m + \frac{1}{2})\lambda $, где $m = 999996$. Это условие интерференционного минимума.
Ответ: На расстоянии R = 2 мм от точки O проходит темная интерференционная полоса.
Другие задания:
Помогло решение? Оставьте отзыв в комментариях ниже.
Присоединяйтесь к Телеграм-группе @top_gdz
ПрисоединитьсяМы подготовили для вас ответ c подробным объяснением домашего задания по физике за 10-11 класс, для упражнения номер 35.6 расположенного на странице 249 к задачнику 2008 года издания для учащихся школ и гимназий.
Теперь на нашем сайте ГДЗ.ТОП вы всегда легко и бесплатно найдёте условие с правильным ответом на вопрос «Как решить ДЗ» и «Как сделать» задание по физике к упражнению №35.6 (с. 249), авторов: Гельфгат (Илья Маркович), Генденштейн (Лев Элевич), Кирик (Леонид Анатольевич), профильный уровень обучения учебного пособия издательства Илекса.