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Лабораторная работа 8, страница 162 - гдз по физике 8 класс учебник Изергин
Авторы: Изергин Э. Т.
Тип: Учебник
Издательство: Русское слово
Год издания: 2019 - 2026
Цвет обложки: синий
ISBN: 978-5-533-01067-2
Популярные ГДЗ в 8 классе
Глава III. Постоянный электрический ток. Параграф 27. Электронагревательные приборы. Предохранители - страница 162.
App\Models\Task {#1024 // 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" => 1492484 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "162" "field_page_end" => "163" "field_url" => "/8-klass/fizika/izergin-uchebnik/labrab-8" "field_display_title" => "Лабораторная работа 8" "field_outside_task" => "0" "field_task_type" => Illuminate\Database\Eloquent\Collection {#331 #items: [] #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 {#1029 #items: [] #escapeWhenCastingToString: false } "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1026 #items: array:1 [ 0 => App\Models\Branch {#342 #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" => 1492175 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Постоянный электрический ток" "field_branch_order" => "III" "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1023 #items: array:1 [ 0 => App\Models\Term {#333 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:7 [ "id" => 29 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Глава" "field_cases" => array:6 [ "field_accusative_case" => "Главу" "field_creative_case" => "Главой" "field_dative_case" => "Главе" "field_genitive_case" => "Главы" "field_nominative_case" => "Глава" "field_prepositional_case" => "Главе" ] "field_page_check_not_needed" => null "field_short_name" => null ] #original: array:7 [ "id" => 29 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Глава" "field_cases" => array:6 [ "field_accusative_case" => "Главу" "field_creative_case" => "Главой" "field_dative_case" => "Главе" "field_genitive_case" => "Главы" "field_nominative_case" => "Глава" "field_prepositional_case" => "Главе" ] "field_page_check_not_needed" => null "field_short_name" => 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_page_start" => "95" "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 {#1033 #items: array:1 [ 0 => App\Models\Book {#1030 #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" => 4168 "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 {#1032 #items: array:1 [ 0 => App\Models\Term {#1034 #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 {#1035 #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" => 5457 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "8" "field_cases" => array:6 [ "field_accusative_case" => "восьмой" "field_creative_case" => "восьмым" "field_dative_case" => "восьмому" "field_genitive_case" => "восьмого" "field_nominative_case" => "восьмой" "field_prepositional_case" => "восьмом" ] "field_translit" => "vosmoj" ] #original: array:6 [ "id" => 5457 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "8" "field_cases" => array:6 [ "field_accusative_case" => "восьмой" "field_creative_case" => "восьмым" "field_dative_case" => "восьмому" "field_genitive_case" => "восьмого" "field_nominative_case" => "восьмой" "field_prepositional_case" => "восьмом" ] "field_translit" => "vosmoj" ] #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 {#1037 #items: array:1 [ 0 => App\Models\Term {#1038 #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" => 5176 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Русское слово" "field_cases" => null "field_translit" => "russkoe slovo" ] #original: array:6 [ "id" => 5176 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Русское слово" "field_cases" => null "field_translit" => "russkoe slovo" ] #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 {#1039 #items: array:1 [ 0 => App\Models\Term {#1040 #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" => 4491 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Изергин" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Эдуард" "field_patronymic" => "Тимофеевич" "field_surname_rp" => null ] #original: array:12 [ "id" => 4491 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Изергин" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Эдуард" "field_patronymic" => "Тимофеевич" "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 {#1041 #items: [] #escapeWhenCastingToString: false } "field_book_type" => Illuminate\Database\Eloquent\Collection {#1042 #items: array:1 [ 0 => App\Models\Term {#1043 #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" => 6671 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Учебник" "field_book_type_foreign" => null "field_cases" => array:6 [ "field_accusative_case" => "учебник" "field_creative_case" => "учебником" "field_dative_case" => "учебнику" "field_genitive_case" => "учебника" "field_nominative_case" => "учебник" "field_prepositional_case" => "учебнике" ] "field_plural_form" => null "field_short_name" => null "field_short_name_foreign" => null "field_translit" => "uchebnik" ] #original: array:10 [ "id" => 6671 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Учебник" "field_book_type_foreign" => null "field_cases" => array:6 [ "field_accusative_case" => "учебник" "field_creative_case" => "учебником" "field_dative_case" => "учебнику" "field_genitive_case" => "учебника" "field_nominative_case" => "учебник" "field_prepositional_case" => "учебнике" ] "field_plural_form" => null "field_short_name" => null "field_short_name_foreign" => null "field_translit" => "uchebnik" ] #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 {#1044 #items: array:1 [ 0 => App\Models\Term {#1045 #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 {#1046 #items: array:1 [ 0 => App\Models\Term {#1047 #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 {#1048 #items: [] #escapeWhenCastingToString: false } "field_umk" => Illuminate\Database\Eloquent\Collection {#1049 #items: [] #escapeWhenCastingToString: false } "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1050 #items: [] #escapeWhenCastingToString: false } "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1051 #items: array:1 [ 0 => App\Models\Term {#1052 #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" => 6706 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "ФГОС (старый)" "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_color" => null "field_end_year" => "2022" "field_start_year" => "2019" "field_translit" => "fgos-old" "field_type" => null ] #original: array:10 [ "id" => 6706 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "ФГОС (старый)" "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_color" => null "field_end_year" => "2022" "field_start_year" => "2019" "field_translit" => "fgos-old" "field_type" => 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_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1053 #items: [] #escapeWhenCastingToString: false } "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1054 #items: [] #escapeWhenCastingToString: false } "field_under_the_edition_degree" => null "field_cover_description" => null "field_publication_year" => "2019" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебник для 8 класса общеобразовательных организаций" "field_allowed" => null "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "417" "field_priority" => null "field_default_folder" => "/fizika_08/izergin-u/" "field_isbn" => "978-5-533-01067-2" "field_cover" => array:1 [ 0 => "/media/fizika_08/izergin-u/covers/cover1.webp?ts=1760998278" ] "field_cover_alts" => array:1 [ 0 => "" ] "field_covers" => array:1 [ 0 => array:4 [ "path" => "/media/fizika_08/izergin-u/covers/cover1.webp?ts=1760998278" "alt" => "" "width" => "1608" "height" => "2576" ] ] "field_popular_book" => "0" "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1055 #items: [] #escapeWhenCastingToString: false } "field_new_book" => Illuminate\Database\Eloquent\Collection {#1056 #items: [] #escapeWhenCastingToString: false } "field_old_book" => Illuminate\Database\Eloquent\Collection {#1057 #items: [] #escapeWhenCastingToString: false } "field_url" => "/8-klass/fizika/izergin-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1058 #items: array:1 [ 0 => App\Models\Term {#1059 #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" => 49 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "синий" "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" => "siniy" ] #original: array:6 [ "id" => 49 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "синий" "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" => "siniy" ] #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" => 379 "subject" => 556 "class_subject" => 492 ] ] #original: array:50 [ "id" => 4168 "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 {#1032} "field_class" => Illuminate\Database\Eloquent\Collection {#1035} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1037} "field_author" => Illuminate\Database\Eloquent\Collection {#1039} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1041} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1042} "field_country" => Illuminate\Database\Eloquent\Collection {#1044} "field_city" => Illuminate\Database\Eloquent\Collection {#1046} "field_series" => Illuminate\Database\Eloquent\Collection {#1048} "field_umk" => Illuminate\Database\Eloquent\Collection {#1049} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1050} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1051} "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1053} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1054} "field_under_the_edition_degree" => null "field_cover_description" => null "field_publication_year" => "2019" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебник для 8 класса общеобразовательных организаций" "field_allowed" => null "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "417" "field_priority" => null "field_default_folder" => "/fizika_08/izergin-u/" "field_isbn" => "978-5-533-01067-2" "field_cover" => array:1 [ 0 => "/media/fizika_08/izergin-u/covers/cover1.webp?ts=1760998278" ] "field_cover_alts" => array:1 [ 0 => "" ] "field_covers" => array:1 [ 0 => array:4 [ "path" => "/media/fizika_08/izergin-u/covers/cover1.webp?ts=1760998278" "alt" => "" "width" => "1608" "height" => "2576" ] ] "field_popular_book" => "0" "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1055} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1056} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1057} "field_url" => "/8-klass/fizika/izergin-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1058} "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "breadcrumbs" => array:3 [ "class" => 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"field_accusative_case" => "Параграф" "field_creative_case" => "Параграфом" "field_dative_case" => "Параграфу" "field_genitive_case" => "Параграфа" "field_nominative_case" => "Параграф" "field_prepositional_case" => "Параграфе" ] "field_page_check_not_needed" => null "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_page_start" => "158" "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 {#1065 #items: array:1 [ 0 => App\Models\Book {#1030} ] #escapeWhenCastingToString: false } "branch_parent" => Illuminate\Database\Eloquent\Collection {#1066 #items: array:1 [ 0 => App\Models\Branch {#1067 #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" => 1492175 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Постоянный электрический ток" "field_branch_order" => "III" "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1068 #items: array:1 [ 0 => App\Models\Term {#1069 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:7 [ …7] #original: array:7 [ …7] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ …1] } ] #escapeWhenCastingToString: false } "field_page_start" => "95" "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" => 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=> null "field_description_bottom" => null "field_branch_cover" => [] "field_branch_covers" => [] "book" => Illuminate\Database\Eloquent\Collection {#1070} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1099} ] #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" => 1492187 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Электронагревательные приборы. Предохранители" "field_branch_order" => "27" "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1063} "field_page_start" => "158" "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 {#1065} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1066} ] #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 {#1100 #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" => 1774789 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1102 #items: array:1 [ 0 => App\Models\Edition {#1103 #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" => 6496 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Условие" "field_order" => "1" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1104 #items: array:1 [ 0 => App\Models\Term {#1105 …30} ] #escapeWhenCastingToString: false } "field_content_type" => "free" "field_content_mode" => "text, image" "field_page_content_mode" => "image" "field_content_text_checked" => "0" "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 {#1106 #items: [] #escapeWhenCastingToString: false } "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1107 #items: [] #escapeWhenCastingToString: false } "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1108 #items: [] #escapeWhenCastingToString: false } "field_content_source" => null ] #original: array:21 [ "id" => 6496 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Условие" "field_order" => "1" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1104} "field_content_type" => "free" "field_content_mode" => "text, image" "field_page_content_mode" => "image" "field_content_text_checked" => "0" "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 {#1106} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1107} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1108} "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" => "1492484" "type" => "task" ] "text" => "<p><strong>Лабораторная работа 8</strong></p><p><strong>Определение КПД электрического нагревателя</strong></p><p><strong>Цель работы: </strong>закрепить навыки сборки электрических цепей, измерения температуры, силы тока и напряжения, навыки расчёта количества теплоты, необходимого для нагревания воды и работы тока.</p><p><strong>Приборы и материалы: </strong>источник тока, амперметр, вольтметр, ключ, калориметр, термометр, реостат, мензурка, нагревательная спираль, часы, провода (7 шт.).</p><p><strong>Порядок выполнения работы</strong></p><p><strong>1.</strong> Налейте с помощью мензурки в калориметр 100 мл воды комнатной температуры. Измерьте температуру воды.</p><p><strong>2.</strong> Соберите электрическую цепь по схеме на рисунке 147.</p><p><strong>3.</strong> После проверки учителем замкните цепь и реостатом установите силу тока 1 А. Значения начальной температуры воды, массы воды, силы тока и напряжения занесите в таблицу 23.</p><p><strong>4.</strong> Нагревайте воду в течение 10–15 мин. После этого разомкните цепь и снова измерьте температуру воды.</p><p><strong>5.</strong> Рассчитайте количество теплоты, полученное водой при нагревании по формуле $Q = cm\Delta T$.</p><p><strong>6.</strong> Рассчитайте количество теплоты, выделенное в проводнике, равное работе тока: $A = IUt$.</p><p><strong>7.</strong> Рассчитайте КПД нагревательной спирали по формуле:</p><p>$\eta = \frac{Q}{A} \cdot 100 \%$.</p><p>Рисунок 147. К заданию 2</p><p>Таблица 23</p><p><strong>m, кг</strong> <strong>t<sub>1</sub>, o C</strong> <strong>t<sub>2</sub>, o C</strong> <strong>I, A</strong> <strong>U, В</strong> <strong>t, с</strong> <strong>Q, Дж</strong> <strong>A, Дж</strong> <strong>η,%</strong></p><p>0,1</p><p><strong>8.</strong> Все результаты занесите в таблицу 23.</p><p><strong>9.</strong> Сделайте вывод.</p>" "img" => array:2 [ 0 => array:5 [ "name" => "8-1.jpg" "alt" => null "width" => "1487" "height" => 962 "path" => "/media/fizika_08/izergin-u/0-labrab/8-1.webp?ts=1761329292" ] 1 => array:5 [ "name" => "8-2.jpg" "alt" => null "width" => "1646" "height" => 1491 "path" => "/media/fizika_08/izergin-u/0-labrab/8-2.webp?ts=1761329292" ] ] ] #original: array:7 [ "id" => 1774789 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1102} "task" => array:2 [ "refs" => "1492484" "type" => "task" ] "text" => "<p><strong>Лабораторная работа 8</strong></p><p><strong>Определение КПД электрического нагревателя</strong></p><p><strong>Цель работы: </strong>закрепить навыки сборки электрических цепей, измерения температуры, силы тока и напряжения, навыки расчёта количества теплоты, необходимого для нагревания воды и работы тока.</p><p><strong>Приборы и материалы: </strong>источник тока, амперметр, вольтметр, ключ, калориметр, термометр, реостат, мензурка, нагревательная спираль, часы, провода (7 шт.).</p><p><strong>Порядок выполнения работы</strong></p><p><strong>1.</strong> Налейте с помощью мензурки в калориметр 100 мл воды комнатной температуры. Измерьте температуру воды.</p><p><strong>2.</strong> Соберите электрическую цепь по схеме на рисунке 147.</p><p><strong>3.</strong> После проверки учителем замкните цепь и реостатом установите силу тока 1 А. Значения начальной температуры воды, массы воды, силы тока и напряжения занесите в таблицу 23.</p><p><strong>4.</strong> Нагревайте воду в течение 10–15 мин. После этого разомкните цепь и снова измерьте температуру воды.</p><p><strong>5.</strong> Рассчитайте количество теплоты, полученное водой при нагревании по формуле $Q = cm\Delta T$.</p><p><strong>6.</strong> Рассчитайте количество теплоты, выделенное в проводнике, равное работе тока: $A = IUt$.</p><p><strong>7.</strong> Рассчитайте КПД нагревательной спирали по формуле:</p><p>$\eta = \frac{Q}{A} \cdot 100 \%$.</p><p>Рисунок 147. К заданию 2</p><p>Таблица 23</p><p><strong>m, кг</strong> <strong>t<sub>1</sub>, o C</strong> <strong>t<sub>2</sub>, o C</strong> <strong>I, A</strong> <strong>U, В</strong> <strong>t, с</strong> <strong>Q, Дж</strong> <strong>A, Дж</strong> <strong>η,%</strong></p><p>0,1</p><p><strong>8.</strong> Все результаты занесите в таблицу 23.</p><p><strong>9.</strong> Сделайте вывод.</p>" "img" => array:2 [ 0 => array:5 [ "name" => "8-1.jpg" "alt" => null "width" => "1487" "height" => 962 "path" => "/media/fizika_08/izergin-u/0-labrab/8-1.webp?ts=1761329292" ] 1 => array:5 [ "name" => "8-2.jpg" "alt" => null "width" => "1646" "height" => 1491 "path" => "/media/fizika_08/izergin-u/0-labrab/8-2.webp?ts=1761329292" ] ] ] #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 {#1109 #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" => 1851961 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1110 #items: array:1 [ 0 => App\Models\Edition {#1111 #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" => 7014 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Решение" "field_order" => "2" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1112 #items: array:1 [ 0 => App\Models\Term {#1113 …30} ] #escapeWhenCastingToString: false } "field_content_type" => "free" "field_content_mode" => "text" "field_page_content_mode" => "" "field_content_text_checked" => "0" "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 {#1114 #items: [] #escapeWhenCastingToString: false } "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1115 #items: [] #escapeWhenCastingToString: false } "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1116 #items: [] #escapeWhenCastingToString: false } "field_content_source" => null ] #original: array:21 [ "id" => 7014 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Решение" "field_order" => "2" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1112} "field_content_type" => "free" "field_content_mode" => "text" "field_page_content_mode" => "" "field_content_text_checked" => "0" "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 {#1114} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1115} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1116} "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" => "1492484" "type" => "task" ] "text" => "<p>Для выполнения лабораторной работы необходимо произвести измерения и расчеты. Так как реальный эксперимент не может быть проведен, мы используем реалистичные данные, которые могли бы быть получены в ходе измерений, и на их основе выполним все вычисления.</p><p>Предположим, что в ходе эксперимента были получены следующие данные:</p><ul><li>Начальная температура воды: $t_1 = 20 \,^{\circ}\text{C}$</li><li>Напряжение в цепи, измеренное вольтметром: $U = 24 \, \text{В}$</li><li>Время нагревания: $t = 10 \, \text{мин}$</li><li>Конечная температура воды: $t_2 = 50 \,^{\circ}\text{C}$</li></ul><p>Остальные данные возьмем из условия задачи и справочников:</p><ul><li>Объем воды: $V = 100 \, \text{мл}$</li><li>Сила тока: $I = 1 \, \text{А}$</li><li>Удельная теплоемкость воды: $c = 4200 \, \frac{\text{Дж}}{\text{кг} \cdot {^{\circ}\text{C}}}$</li><li>Плотность воды: $\rho = 1000 \, \frac{\text{кг}}{\text{м}^3}$</li></ul><p><strong>Дано:</strong></p><p>$V = 100 \, \text{мл}$</p><p>$t_1 = 20 \,^{\circ}\text{C}$</p><p>$t_2 = 50 \,^{\circ}\text{C}$</p><p>$I = 1 \, \text{А}$</p><p>$U = 24 \, \text{В}$</p><p>$t = 10 \, \text{мин}$</p><p>$c = 4200 \, \frac{\text{Дж}}{\text{кг} \cdot {^{\circ}\text{C}}}$</p><p>$\rho = 1000 \, \frac{\text{кг}}{\text{м}^3}$</p><p><strong>Перевод в систему СИ:</strong></p><p>$V = 100 \, \text{мл} = 100 \cdot 10^{-6} \, \text{м}^3 = 10^{-4} \, \text{м}^3$</p><p>$t = 10 \, \text{мин} = 10 \cdot 60 \, \text{с} = 600 \, \text{с}$</p><br><strong>Найти:</strong><p>$\text{Q}$ - ?</p><p>$\text{A}$ - ?</p><p>$\eta$ - ?</p><br><strong>Решение:</strong><p><strong>5.</strong> Рассчитайте количество теплоты, полученное водой при нагревании по формуле $Q = cm\Delta T$.</p><p>Сначала найдем массу воды, зная её объем и плотность:</p><p>$m = \rho \cdot V = 1000 \, \frac{\text{кг}}{\text{м}^3} \cdot 10^{-4} \, \text{м}^3 = 0,1 \, \text{кг}$</p><p>Теперь найдем изменение температуры воды:</p><p>$\Delta T = t_2 - t_1 = 50 \,^{\circ}\text{C} - 20 \,^{\circ}\text{C} = 30 \,^{\circ}\text{C}$</p><p>Рассчитаем количество теплоты (полезную энергию), полученное водой:</p><p>$Q = c \cdot m \cdot \Delta T = 4200 \, \frac{\text{Дж}}{\text{кг} \cdot {^{\circ}\text{C}}} \cdot 0,1 \, \text{кг} \cdot 30 \,^{\circ}\text{C} = 12600 \, \text{Дж}$</p><p><strong>Ответ:</strong> $Q = 12600 \, \text{Дж}$</p><p><strong>6.</strong> Рассчитайте количество теплоты, выделенное в проводнике, равное работе тока: $A = IUt$.</p><p>Рассчитаем работу электрического тока (затраченную энергию):</p><p>$A = I \cdot U \cdot t = 1 \, \text{А} \cdot 24 \, \text{В} \cdot 600 \, \text{с} = 14400 \, \text{Дж}$</p><p><strong>Ответ:</strong> $A = 14400 \, \text{Дж}$</p><p><strong>7.</strong> Рассчитайте КПД нагревательной спирали по формуле: $\eta = \frac{Q}{A} \cdot 100\%$.</p><p>Теперь, зная полезную и затраченную энергию, рассчитаем коэффициент полезного действия (КПД) нагревателя:</p><p>$\eta = \frac{Q}{A} \cdot 100\% = \frac{12600 \, \text{Дж}}{14400 \, \text{Дж}} \cdot 100\% = 0,875 \cdot 100\% = 87,5\%$</p><p><strong>Ответ:</strong> $\eta = 87,5\%$</p><p><strong>8.</strong> Все результаты занесите в таблицу 23.</p><p>Заполненная таблица с результатами измерений и вычислений:</p><div class="table-wrap"><table border="1" style="border: 1px solid rgb(0, 0, 0);"><thead><tr><th style="border: 1px solid rgb(0, 0, 0);">m, кг</th><th style="border: 1px solid rgb(0, 0, 0);">t<sub>1</sub>, °C</th><th style="border: 1px solid rgb(0, 0, 0);">t<sub>2</sub>, °C</th><th style="border: 1px solid rgb(0, 0, 0);">I, А</th><th style="border: 1px solid rgb(0, 0, 0);">U, В</th><th style="border: 1px solid rgb(0, 0, 0);">t, с</th><th style="border: 1px solid rgb(0, 0, 0);">Q, Дж</th><th style="border: 1px solid rgb(0, 0, 0);">A, Дж</th><th style="border: 1px solid rgb(0, 0, 0);">η, %</th></tr></thead><tbody><tr><td style="border: 1px solid rgb(0, 0, 0);">0,1</td><td style="border: 1px solid rgb(0, 0, 0);">20</td><td style="border: 1px solid rgb(0, 0, 0);">50</td><td style="border: 1px solid rgb(0, 0, 0);">1</td><td style="border: 1px solid rgb(0, 0, 0);">24</td><td style="border: 1px solid rgb(0, 0, 0);">600</td><td style="border: 1px solid rgb(0, 0, 0);">12600</td><td style="border: 1px solid rgb(0, 0, 0);">14400</td><td style="border: 1px solid rgb(0, 0, 0);">87,5</td></tr></tbody></table></div><p><strong>9.</strong> Сделайте вывод.</p><p>В ходе выполнения лабораторной работы был определен КПД электрического нагревателя. Были произведены измерения начальной и конечной температуры воды, силы тока и напряжения в цепи, а также времени нагрева. На основе этих данных было рассчитано количество теплоты, полученное водой (полезная работа $Q = 12600 \, \text{Дж}$), и работа, совершенная электрическим током (затраченная работа $A = 14400 \, \text{Дж}$).</p><p>Полученный КПД нагревателя составил $\eta = 87,5\%$. Это значение меньше 100%, что является закономерным результатом, поскольку в реальных условиях часть энергии, выделяемой нагревательным элементом, рассеивается в окружающую среду, а также идет на нагрев самого калориметра и термометра, а не только воды. Таким образом, не вся затраченная электрическая энергия превращается в полезную тепловую энергию для нагрева воды.</p>" ] #original: array:6 [ "id" => 1851961 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1110} "task" => array:2 [ "refs" => "1492484" "type" => "task" ] "text" => "<p>Для выполнения лабораторной работы необходимо произвести измерения и расчеты. Так как реальный эксперимент не может быть проведен, мы используем реалистичные данные, которые могли бы быть получены в ходе измерений, и на их основе выполним все вычисления.</p><p>Предположим, что в ходе эксперимента были получены следующие данные:</p><ul><li>Начальная температура воды: $t_1 = 20 \,^{\circ}\text{C}$</li><li>Напряжение в цепи, измеренное вольтметром: $U = 24 \, \text{В}$</li><li>Время нагревания: $t = 10 \, \text{мин}$</li><li>Конечная температура воды: $t_2 = 50 \,^{\circ}\text{C}$</li></ul><p>Остальные данные возьмем из условия задачи и справочников:</p><ul><li>Объем воды: $V = 100 \, \text{мл}$</li><li>Сила тока: $I = 1 \, \text{А}$</li><li>Удельная теплоемкость воды: $c = 4200 \, \frac{\text{Дж}}{\text{кг} \cdot {^{\circ}\text{C}}}$</li><li>Плотность воды: $\rho = 1000 \, \frac{\text{кг}}{\text{м}^3}$</li></ul><p><strong>Дано:</strong></p><p>$V = 100 \, \text{мл}$</p><p>$t_1 = 20 \,^{\circ}\text{C}$</p><p>$t_2 = 50 \,^{\circ}\text{C}$</p><p>$I = 1 \, \text{А}$</p><p>$U = 24 \, \text{В}$</p><p>$t = 10 \, \text{мин}$</p><p>$c = 4200 \, \frac{\text{Дж}}{\text{кг} \cdot {^{\circ}\text{C}}}$</p><p>$\rho = 1000 \, \frac{\text{кг}}{\text{м}^3}$</p><p><strong>Перевод в систему СИ:</strong></p><p>$V = 100 \, \text{мл} = 100 \cdot 10^{-6} \, \text{м}^3 = 10^{-4} \, \text{м}^3$</p><p>$t = 10 \, \text{мин} = 10 \cdot 60 \, \text{с} = 600 \, \text{с}$</p><br><strong>Найти:</strong><p>$\text{Q}$ - ?</p><p>$\text{A}$ - ?</p><p>$\eta$ - ?</p><br><strong>Решение:</strong><p><strong>5.</strong> Рассчитайте количество теплоты, полученное водой при нагревании по формуле $Q = cm\Delta T$.</p><p>Сначала найдем массу воды, зная её объем и плотность:</p><p>$m = \rho \cdot V = 1000 \, \frac{\text{кг}}{\text{м}^3} \cdot 10^{-4} \, \text{м}^3 = 0,1 \, \text{кг}$</p><p>Теперь найдем изменение температуры воды:</p><p>$\Delta T = t_2 - t_1 = 50 \,^{\circ}\text{C} - 20 \,^{\circ}\text{C} = 30 \,^{\circ}\text{C}$</p><p>Рассчитаем количество теплоты (полезную энергию), полученное водой:</p><p>$Q = c \cdot m \cdot \Delta T = 4200 \, \frac{\text{Дж}}{\text{кг} \cdot {^{\circ}\text{C}}} \cdot 0,1 \, \text{кг} \cdot 30 \,^{\circ}\text{C} = 12600 \, \text{Дж}$</p><p><strong>Ответ:</strong> $Q = 12600 \, \text{Дж}$</p><p><strong>6.</strong> Рассчитайте количество теплоты, выделенное в проводнике, равное работе тока: $A = IUt$.</p><p>Рассчитаем работу электрического тока (затраченную энергию):</p><p>$A = I \cdot U \cdot t = 1 \, \text{А} \cdot 24 \, \text{В} \cdot 600 \, \text{с} = 14400 \, \text{Дж}$</p><p><strong>Ответ:</strong> $A = 14400 \, \text{Дж}$</p><p><strong>7.</strong> Рассчитайте КПД нагревательной спирали по формуле: $\eta = \frac{Q}{A} \cdot 100\%$.</p><p>Теперь, зная полезную и затраченную энергию, рассчитаем коэффициент полезного действия (КПД) нагревателя:</p><p>$\eta = \frac{Q}{A} \cdot 100\% = \frac{12600 \, \text{Дж}}{14400 \, \text{Дж}} \cdot 100\% = 0,875 \cdot 100\% = 87,5\%$</p><p><strong>Ответ:</strong> $\eta = 87,5\%$</p><p><strong>8.</strong> Все результаты занесите в таблицу 23.</p><p>Заполненная таблица с результатами измерений и вычислений:</p><div class="table-wrap"><table border="1" style="border: 1px solid rgb(0, 0, 0);"><thead><tr><th style="border: 1px solid rgb(0, 0, 0);">m, кг</th><th style="border: 1px solid rgb(0, 0, 0);">t<sub>1</sub>, °C</th><th style="border: 1px solid rgb(0, 0, 0);">t<sub>2</sub>, °C</th><th style="border: 1px solid rgb(0, 0, 0);">I, А</th><th style="border: 1px solid rgb(0, 0, 0);">U, В</th><th style="border: 1px solid rgb(0, 0, 0);">t, с</th><th style="border: 1px solid rgb(0, 0, 0);">Q, Дж</th><th style="border: 1px solid rgb(0, 0, 0);">A, Дж</th><th style="border: 1px solid rgb(0, 0, 0);">η, %</th></tr></thead><tbody><tr><td style="border: 1px solid rgb(0, 0, 0);">0,1</td><td style="border: 1px solid rgb(0, 0, 0);">20</td><td style="border: 1px solid rgb(0, 0, 0);">50</td><td style="border: 1px solid rgb(0, 0, 0);">1</td><td style="border: 1px solid rgb(0, 0, 0);">24</td><td style="border: 1px solid rgb(0, 0, 0);">600</td><td style="border: 1px solid rgb(0, 0, 0);">12600</td><td style="border: 1px solid rgb(0, 0, 0);">14400</td><td style="border: 1px solid rgb(0, 0, 0);">87,5</td></tr></tbody></table></div><p><strong>9.</strong> Сделайте вывод.</p><p>В ходе выполнения лабораторной работы был определен КПД электрического нагревателя. Были произведены измерения начальной и конечной температуры воды, силы тока и напряжения в цепи, а также времени нагрева. На основе этих данных было рассчитано количество теплоты, полученное водой (полезная работа $Q = 12600 \, \text{Дж}$), и работа, совершенная электрическим током (затраченная работа $A = 14400 \, \text{Дж}$).</p><p>Полученный КПД нагревателя составил $\eta = 87,5\%$. Это значение меньше 100%, что является закономерным результатом, поскольку в реальных условиях часть энергии, выделяемой нагревательным элементом, рассеивается в окружающую среду, а также идет на нагрев самого калориметра и термометра, а не только воды. Таким образом, не вся затраченная электрическая энергия превращается в полезную тепловую энергию для нагрева воды.</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" => "1492485" "type" => "task" ] "previous" => array:2 [ "refs" => "1492483" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1117 #items: array:1 [ 0 => App\Models\Book {#1030} ] #escapeWhenCastingToString: false } "page" => Illuminate\Database\Eloquent\Collection {#1292 #items: array:1 [ 0 => App\Models\BookPage {#1122 #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" => 1492054 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "162" "field_url" => "/8-klass/fizika/izergin-uchebnik/page-162" "field_display_title" => "162" "field_folder" => "1" "field_image_name" => "162" "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1134 #items: [] #escapeWhenCastingToString: false } "field_weight" => "0" "field_book_parent" => Illuminate\Database\Eloquent\Collection {#1133 #items: array:1 [ 0 => App\Models\Book {#1135 #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" => 4168 "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 {#1136 #items: array:1 [ 0 => App\Models\Term {#1137 …30} ] #escapeWhenCastingToString: false } "field_class" => Illuminate\Database\Eloquent\Collection {#1138 #items: array:1 [ 0 => App\Models\Term {#1139 …30} ] #escapeWhenCastingToString: false } "field_publisher" => Illuminate\Database\Eloquent\Collection {#1140 #items: array:1 [ 0 => App\Models\Term {#1141 …30} ] #escapeWhenCastingToString: false } "field_author" => Illuminate\Database\Eloquent\Collection {#1142 #items: array:1 [ 0 => App\Models\Term {#1143 …30} ] #escapeWhenCastingToString: false } "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1144 #items: [] #escapeWhenCastingToString: false } "field_book_type" => Illuminate\Database\Eloquent\Collection {#1145 #items: array:1 [ 0 => App\Models\Term {#1146 …30} ] #escapeWhenCastingToString: false } "field_country" => Illuminate\Database\Eloquent\Collection {#1147 #items: array:1 [ 0 => App\Models\Term {#1148 …30} ] #escapeWhenCastingToString: false } "field_city" => Illuminate\Database\Eloquent\Collection {#1149 #items: array:1 [ 0 => App\Models\Term {#1150 …30} ] #escapeWhenCastingToString: false } "field_series" => Illuminate\Database\Eloquent\Collection {#1151 #items: [] #escapeWhenCastingToString: false } "field_umk" => Illuminate\Database\Eloquent\Collection {#1152 #items: [] #escapeWhenCastingToString: false } "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1153 #items: [] #escapeWhenCastingToString: false } "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1154 #items: array:1 [ 0 => App\Models\Term {#1155 …30} ] #escapeWhenCastingToString: false } "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1156 #items: [] #escapeWhenCastingToString: false } "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1157 #items: [] #escapeWhenCastingToString: false } "field_under_the_edition_degree" => null "field_cover_description" => null "field_publication_year" => "2019" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебник для 8 класса общеобразовательных организаций" "field_allowed" => null "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "417" "field_priority" => null "field_default_folder" => "/fizika_08/izergin-u/" "field_isbn" => "978-5-533-01067-2" "field_cover" => array:1 [ 0 => "/media/fizika_08/izergin-u/covers/cover1.webp?ts=1760998278" ] "field_cover_alts" => array:1 [ 0 => "" ] "field_covers" => array:1 [ 0 => array:4 [ "path" => "/media/fizika_08/izergin-u/covers/cover1.webp?ts=1760998278" "alt" => "" "width" => "1608" "height" => "2576" ] ] "field_popular_book" => "0" "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1158 #items: [] #escapeWhenCastingToString: false } "field_new_book" => Illuminate\Database\Eloquent\Collection {#1159 #items: [] #escapeWhenCastingToString: false } "field_old_book" => Illuminate\Database\Eloquent\Collection {#1160 #items: [] #escapeWhenCastingToString: false } "field_url" => "/8-klass/fizika/izergin-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1161 #items: array:1 [ 0 => App\Models\Term {#1162 …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" => 379 "subject" => 556 "class_subject" => 492 ] ] #original: array:50 [ "id" => 4168 "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 {#1136} "field_class" => Illuminate\Database\Eloquent\Collection {#1138} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1140} "field_author" => Illuminate\Database\Eloquent\Collection {#1142} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1144} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1145} "field_country" => Illuminate\Database\Eloquent\Collection {#1147} "field_city" => Illuminate\Database\Eloquent\Collection {#1149} "field_series" => Illuminate\Database\Eloquent\Collection {#1151} "field_umk" => Illuminate\Database\Eloquent\Collection {#1152} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1153} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1154} "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1156} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1157} "field_under_the_edition_degree" => null "field_cover_description" => null "field_publication_year" => "2019" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебник для 8 класса общеобразовательных организаций" "field_allowed" => null "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "417" "field_priority" => null "field_default_folder" => "/fizika_08/izergin-u/" "field_isbn" => "978-5-533-01067-2" "field_cover" => array:1 [ 0 => "/media/fizika_08/izergin-u/covers/cover1.webp?ts=1760998278" ] "field_cover_alts" => array:1 [ 0 => "" ] "field_covers" => array:1 [ 0 => array:4 [ "path" => "/media/fizika_08/izergin-u/covers/cover1.webp?ts=1760998278" "alt" => "" "width" => "1608" "height" => "2576" ] ] "field_popular_book" => "0" "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1158} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1159} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1160} "field_url" => "/8-klass/fizika/izergin-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1161} "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "breadcrumbs" => array:3 [ "class" => 379 "subject" => 556 "class_subject" => 492 ] ] #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 "edition_groups" => Illuminate\Database\Eloquent\Collection {#1163 #items: [] #escapeWhenCastingToString: false } "content" => Illuminate\Database\Eloquent\Collection {#1164 #items: array:1 [ 0 => App\Models\Element {#1165 #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" => 1774955 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1166 #items: array:1 [ 0 => App\Models\Edition {#1167 …30} ] #escapeWhenCastingToString: false } "book_page" => array:2 [ "refs" => "1492054" "type" => "book_page" ] "img" => array:1 [ 0 => array:5 [ "name" => "162-1.jpg" "alt" => null "width" => "1901" "height" => 2557 "path" => "/media/fizika_08/izergin-u/0-1/162-1.webp?ts=1761329731" ] ] ] #original: array:6 [ "id" => 1774955 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1166} "book_page" => array:2 [ "refs" => "1492054" "type" => "book_page" ] "img" => array:1 [ 0 => array:5 [ "name" => "162-1.jpg" "alt" => null "width" => "1901" "height" => 2557 "path" => "/media/fizika_08/izergin-u/0-1/162-1.webp?ts=1761329731" ] ] ] #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" => "1492055" "type" => "book_page" ] "previous" => array:2 [ "refs" => "1492053" "type" => "book_page" ] "tasks" => Illuminate\Database\Eloquent\Collection {#1173 #items: array:6 [ 0 => App\Models\Task {#1174 #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" => 1492479 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "162" "field_page_end" => null "field_url" => "/8-klass/fizika/izergin-uchebnik/27-1" "field_display_title" => "1" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1175 #items: array:1 [ 0 => App\Models\Term {#1176 …30} ] #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 {#1177 #items: [] #escapeWhenCastingToString: false } "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1178 #items: array:1 [ 0 => App\Models\Branch {#1179 …30} ] #escapeWhenCastingToString: false } "parent_branches" => Illuminate\Database\Eloquent\Collection {#1212 #items: array:2 [ 0 => App\Models\Branch {#1213 …30} 1 => App\Models\Branch {#1218 …30} ] #escapeWhenCastingToString: false } "content" => Illuminate\Database\Eloquent\Collection {#1223 #items: array:2 [ 0 => App\Models\Element {#1224 …30} 1 => App\Models\Element {#1226 …30} ] #escapeWhenCastingToString: false } "next" => array:2 [ "refs" => "1492480" "type" => "task" ] "previous" => array:2 [ "refs" => "1492478" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1234 #items: array:1 [ 0 => App\Models\Book {#1135} ] #escapeWhenCastingToString: false } "page" => array:2 [ "refs" => "1492054" "type" => "book_page" ] ] #original: array:24 [ "id" => 1492479 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "162" "field_page_end" => null "field_url" => "/8-klass/fizika/izergin-uchebnik/27-1" "field_display_title" => "1" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1175} "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 {#1177} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1178} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1212} "content" => Illuminate\Database\Eloquent\Collection {#1223} "next" => array:2 [ "refs" => "1492480" "type" => "task" ] "previous" => array:2 [ "refs" => "1492478" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1234} "page" => array:2 [ "refs" => "1492054" "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 {#1235 #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" => 1492480 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "162" "field_page_end" => null "field_url" => "/8-klass/fizika/izergin-uchebnik/27-2" "field_display_title" => "2" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1236 #items: array:1 [ 0 => App\Models\Term {#1176 …30} ] #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 {#1237 #items: [] #escapeWhenCastingToString: false } "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1238 #items: array:1 [ 0 => App\Models\Branch {#1213 …30} ] #escapeWhenCastingToString: false } "parent_branches" => Illuminate\Database\Eloquent\Collection {#1239 #items: array:2 [ 0 => App\Models\Branch {#1213 …30} 1 => App\Models\Branch {#1218 …30} ] #escapeWhenCastingToString: false } "content" => Illuminate\Database\Eloquent\Collection {#1240 #items: array:2 [ 0 => App\Models\Element {#1241 …30} 1 => App\Models\Element {#1243 …30} ] #escapeWhenCastingToString: false } "next" => array:2 [ "refs" => "1492481" "type" => "task" ] "previous" => array:2 [ "refs" => "1492479" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1245 #items: array:1 [ 0 => App\Models\Book {#1135} ] #escapeWhenCastingToString: false } "page" => array:2 [ "refs" => "1492054" "type" => "book_page" ] ] #original: array:24 [ "id" => 1492480 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "162" "field_page_end" => null "field_url" => "/8-klass/fizika/izergin-uchebnik/27-2" "field_display_title" => "2" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1236} "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 {#1237} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1238} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1239} "content" => Illuminate\Database\Eloquent\Collection {#1240} "next" => array:2 [ "refs" => "1492481" "type" => "task" ] "previous" => array:2 [ "refs" => "1492479" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1245} "page" => array:2 [ "refs" => "1492054" "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 => "*" ] } 2 => App\Models\Task {#1246 #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" => 1492481 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "162" "field_page_end" => null "field_url" => "/8-klass/fizika/izergin-uchebnik/27-3" "field_display_title" => "3" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1247 #items: array:1 [ 0 => App\Models\Term {#1176 …30} ] #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 {#1248 #items: [] #escapeWhenCastingToString: false } "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1249 #items: array:1 [ 0 => App\Models\Branch {#1213 …30} ] #escapeWhenCastingToString: false } "parent_branches" => Illuminate\Database\Eloquent\Collection {#1250 #items: array:2 [ 0 => App\Models\Branch {#1213 …30} 1 => App\Models\Branch {#1218 …30} ] #escapeWhenCastingToString: false } "content" => Illuminate\Database\Eloquent\Collection {#1251 #items: array:2 [ 0 => App\Models\Element {#1252 …30} 1 => App\Models\Element {#1254 …30} ] #escapeWhenCastingToString: false } "next" => array:2 [ "refs" => "1492482" "type" => "task" ] "previous" => array:2 [ "refs" => "1492480" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1256 #items: array:1 [ 0 => App\Models\Book {#1135} ] #escapeWhenCastingToString: false } "page" => array:2 [ "refs" => "1492054" "type" => "book_page" ] ] #original: array:24 [ "id" => 1492481 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "162" "field_page_end" => null "field_url" => "/8-klass/fizika/izergin-uchebnik/27-3" "field_display_title" => "3" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1247} "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 {#1248} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1249} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1250} "content" => Illuminate\Database\Eloquent\Collection {#1251} "next" => array:2 [ "refs" => "1492482" "type" => "task" ] "previous" => array:2 [ "refs" => "1492480" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1256} "page" => array:2 [ "refs" => "1492054" "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 => "*" ] } 3 => App\Models\Task {#1257 #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" => 1492482 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "162" "field_page_end" => null "field_url" => "/8-klass/fizika/izergin-uchebnik/27-4" "field_display_title" => "4" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1258 #items: array:1 [ 0 => App\Models\Term {#1176 …30} ] #escapeWhenCastingToString: false } 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Лабораторная работа 8 (с. 162)
Условие. Лабораторная работа 8 (с. 162)
скриншот условия
Лабораторная работа 8
Определение КПД электрического нагревателя
Цель работы: закрепить навыки сборки электрических цепей, измерения температуры, силы тока и напряжения, навыки расчёта количества теплоты, необходимого для нагревания воды и работы тока.
Приборы и материалы: источник тока, амперметр, вольтметр, ключ, калориметр, термометр, реостат, мензурка, нагревательная спираль, часы, провода (7 шт.).
Порядок выполнения работы
1. Налейте с помощью мензурки в калориметр 100 мл воды комнатной температуры. Измерьте температуру воды.
2. Соберите электрическую цепь по схеме на рисунке 147.
3. После проверки учителем замкните цепь и реостатом установите силу тока 1 А. Значения начальной температуры воды, массы воды, силы тока и напряжения занесите в таблицу 23.
4. Нагревайте воду в течение 10–15 мин. После этого разомкните цепь и снова измерьте температуру воды.
5. Рассчитайте количество теплоты, полученное водой при нагревании по формуле $Q = cm\Delta T$.
6. Рассчитайте количество теплоты, выделенное в проводнике, равное работе тока: $A = IUt$.
7. Рассчитайте КПД нагревательной спирали по формуле:
$\eta = \frac{Q}{A} \cdot 100 \%$.
Рисунок 147. К заданию 2
Таблица 23
m, кг t1, o C t2, o C I, A U, В t, с Q, Дж A, Дж η,%
0,1
8. Все результаты занесите в таблицу 23.
9. Сделайте вывод.
Решение. Лабораторная работа 8 (с. 162)
Для выполнения лабораторной работы необходимо произвести измерения и расчеты. Так как реальный эксперимент не может быть проведен, мы используем реалистичные данные, которые могли бы быть получены в ходе измерений, и на их основе выполним все вычисления.
Предположим, что в ходе эксперимента были получены следующие данные:
- Начальная температура воды: $t_1 = 20 \,^{\circ}\text{C}$
- Напряжение в цепи, измеренное вольтметром: $U = 24 \, \text{В}$
- Время нагревания: $t = 10 \, \text{мин}$
- Конечная температура воды: $t_2 = 50 \,^{\circ}\text{C}$
Остальные данные возьмем из условия задачи и справочников:
- Объем воды: $V = 100 \, \text{мл}$
- Сила тока: $I = 1 \, \text{А}$
- Удельная теплоемкость воды: $c = 4200 \, \frac{\text{Дж}}{\text{кг} \cdot {^{\circ}\text{C}}}$
- Плотность воды: $\rho = 1000 \, \frac{\text{кг}}{\text{м}^3}$
Дано:
$V = 100 \, \text{мл}$
$t_1 = 20 \,^{\circ}\text{C}$
$t_2 = 50 \,^{\circ}\text{C}$
$I = 1 \, \text{А}$
$U = 24 \, \text{В}$
$t = 10 \, \text{мин}$
$c = 4200 \, \frac{\text{Дж}}{\text{кг} \cdot {^{\circ}\text{C}}}$
$\rho = 1000 \, \frac{\text{кг}}{\text{м}^3}$
Перевод в систему СИ:
$V = 100 \, \text{мл} = 100 \cdot 10^{-6} \, \text{м}^3 = 10^{-4} \, \text{м}^3$
$t = 10 \, \text{мин} = 10 \cdot 60 \, \text{с} = 600 \, \text{с}$
Найти:
$\text{Q}$ - ?
$\text{A}$ - ?
$\eta$ - ?
Решение:
5. Рассчитайте количество теплоты, полученное водой при нагревании по формуле $Q = cm\Delta T$.
Сначала найдем массу воды, зная её объем и плотность:
$m = \rho \cdot V = 1000 \, \frac{\text{кг}}{\text{м}^3} \cdot 10^{-4} \, \text{м}^3 = 0,1 \, \text{кг}$
Теперь найдем изменение температуры воды:
$\Delta T = t_2 - t_1 = 50 \,^{\circ}\text{C} - 20 \,^{\circ}\text{C} = 30 \,^{\circ}\text{C}$
Рассчитаем количество теплоты (полезную энергию), полученное водой:
$Q = c \cdot m \cdot \Delta T = 4200 \, \frac{\text{Дж}}{\text{кг} \cdot {^{\circ}\text{C}}} \cdot 0,1 \, \text{кг} \cdot 30 \,^{\circ}\text{C} = 12600 \, \text{Дж}$
Ответ: $Q = 12600 \, \text{Дж}$
6. Рассчитайте количество теплоты, выделенное в проводнике, равное работе тока: $A = IUt$.
Рассчитаем работу электрического тока (затраченную энергию):
$A = I \cdot U \cdot t = 1 \, \text{А} \cdot 24 \, \text{В} \cdot 600 \, \text{с} = 14400 \, \text{Дж}$
Ответ: $A = 14400 \, \text{Дж}$
7. Рассчитайте КПД нагревательной спирали по формуле: $\eta = \frac{Q}{A} \cdot 100\%$.
Теперь, зная полезную и затраченную энергию, рассчитаем коэффициент полезного действия (КПД) нагревателя:
$\eta = \frac{Q}{A} \cdot 100\% = \frac{12600 \, \text{Дж}}{14400 \, \text{Дж}} \cdot 100\% = 0,875 \cdot 100\% = 87,5\%$
Ответ: $\eta = 87,5\%$
8. Все результаты занесите в таблицу 23.
Заполненная таблица с результатами измерений и вычислений:
| m, кг | t1, °C | t2, °C | I, А | U, В | t, с | Q, Дж | A, Дж | η, % |
|---|---|---|---|---|---|---|---|---|
| 0,1 | 20 | 50 | 1 | 24 | 600 | 12600 | 14400 | 87,5 |
9. Сделайте вывод.
В ходе выполнения лабораторной работы был определен КПД электрического нагревателя. Были произведены измерения начальной и конечной температуры воды, силы тока и напряжения в цепи, а также времени нагрева. На основе этих данных было рассчитано количество теплоты, полученное водой (полезная работа $Q = 12600 \, \text{Дж}$), и работа, совершенная электрическим током (затраченная работа $A = 14400 \, \text{Дж}$).
Полученный КПД нагревателя составил $\eta = 87,5\%$. Это значение меньше 100%, что является закономерным результатом, поскольку в реальных условиях часть энергии, выделяемой нагревательным элементом, рассеивается в окружающую среду, а также идет на нагрев самого калориметра и термометра, а не только воды. Таким образом, не вся затраченная электрическая энергия превращается в полезную тепловую энергию для нагрева воды.
Другие задания:
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