Номер 38, страница 179, часть 1 - гдз по физике 9 класс учебник Генденштейн, Булатова

Авторы: Генденштейн Л. Э., Булатова А. А., Корнильев И. Н., Кошкина А. В.

Тип: Учебник

Издательство: Бином

Год издания: 2016 - 2026

Часть: 1

Цвет обложки: бирюзовый

ISBN: 978-5-9963-3062-1

Часть 1. Механические явления. Глава IV. Механические колебания и волны. Параграф 21. Механические колебания - номер 38, страница 179.

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                            "name" => "Бином"
                            "field_cases" => null
                            "field_translit" => "binom"
                          ]
                          #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 {#1203
                      #items: array:4 [
                        0 => App\Models\Term {#1204
                          #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 => "*"
                          ]
                        }
                        1 => App\Models\Term {#1205
                          #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" => 3936
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Булатова"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Альбина"
                            "field_patronymic" => "Александрова"
                            "field_surname_rp" => null
                          ]
                          #original: array:12 [
                            "id" => 3936
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Булатова"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Альбина"
                            "field_patronymic" => "Александрова"
                            "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 => "*"
                          ]
                        }
                        2 => App\Models\Term {#1206
                          #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" => 4679
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Корнильев"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Игорь"
                            "field_patronymic" => "Николаевич"
                            "field_surname_rp" => null
                          ]
                          #original: array:12 [
                            "id" => 4679
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Корнильев"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Игорь"
                            "field_patronymic" => "Николаевич"
                            "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 => "*"
                          ]
                        }
                        3 => App\Models\Term {#1207
                          #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" => 4758
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Кошкина"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Анжелика"
                            "field_patronymic" => "Васильевна"
                            "field_surname_rp" => null
                          ]
                          #original: array:12 [
                            "id" => 4758
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Кошкина"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Анжелика"
                            "field_patronymic" => "Васильевна"
                            "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 {#1208
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1209
                      #items: array:1 [
                        0 => App\Models\Term {#1210
                          #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 [ …6]
                            "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 [ …6]
                            "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 {#1211
                      #items: array:1 [
                        0 => App\Models\Term {#1212
                          #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 [ …6]
                            "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 [ …6]
                            "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 {#1213
                      #items: array:1 [
                        0 => App\Models\Term {#1214
                          #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 [ …6]
                            "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 [ …6]
                            "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 {#1215
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1216
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1217
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1218
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_publication_number" => null
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1219
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1220
                      #items: array:1 [
                        0 => App\Models\Term {#1221
                          #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" => 5395
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Орлов"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Владимир"
                            "field_patronymic" => "Алексеевич"
                            "field_surname_rp" => "Орлова"
                          ]
                          #original: array:12 [
                            "id" => 5395
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Орлов"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Владимир"
                            "field_patronymic" => "Алексеевич"
                            "field_surname_rp" => "Орлова"
                          ]
                          #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_under_the_edition_degree" => null
                    "field_cover_description" => null
                    "field_publication_year" => "2016"
                    "field_publication_year_until" => null
                    "field_part" => "1, 2"
                    "field_part_writing" => "Часть"
                    "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" => "1111"
                    "field_priority" => null
                    "field_default_folder" => "/fizika_09/gendenshtejn-u/"
                    "field_isbn" => "978-5-9963-3062-1"
                    "field_cover" => array:2 [
                      0 => "/media/fizika_09/gendenshtejn-u/covers/cover1.webp?ts=1759256052"
                      1 => "/media/fizika_09/gendenshtejn-u/covers/cover2.webp?ts=1759256052"
                    ]
                    "field_cover_alts" => array:2 [
                      0 => ""
                      1 => ""
                    ]
                    "field_covers" => array:2 [
                      0 => array:4 [
                        "path" => "/media/fizika_09/gendenshtejn-u/covers/cover1.webp?ts=1759256052"
                        "alt" => ""
                        "width" => "1863"
                        "height" => "2813"
                      ]
                      1 => array:4 [
                        "path" => "/media/fizika_09/gendenshtejn-u/covers/cover2.webp?ts=1759256052"
                        "alt" => ""
                        "width" => "1863"
                        "height" => "2809"
                      ]
                    ]
                    "field_popular_book" => "0"
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1222
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1223
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1224
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_url" => "/9-klass/fizika/gendenshtejn-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1225
                      #items: array:1 [
                        0 => App\Models\Term {#1226
                          #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" => 6978
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "бирюзовый"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "biruzovyy"
                          ]
                          #original: array:6 [
                            "id" => 6978
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "бирюзовый"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "biruzovyy"
                          ]
                          #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" => 380
                      "subject" => 556
                      "class_subject" => 493
                    ]
                  ]
                  #original: array:50 [
                    "id" => 2980
                    "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 {#1198}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1199}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1201}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1203}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1208}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1209}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1211}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1213}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1215}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1216}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1217}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1218}
                    "field_publication_number" => null
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1219}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1220}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => null
                    "field_publication_year" => "2016"
                    "field_publication_year_until" => null
                    "field_part" => "1, 2"
                    "field_part_writing" => "Часть"
                    "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" => "1111"
                    "field_priority" => null
                    "field_default_folder" => "/fizika_09/gendenshtejn-u/"
                    "field_isbn" => "978-5-9963-3062-1"
                    "field_cover" => array:2 [
                      0 => "/media/fizika_09/gendenshtejn-u/covers/cover1.webp?ts=1759256052"
                      1 => "/media/fizika_09/gendenshtejn-u/covers/cover2.webp?ts=1759256052"
                    ]
                    "field_cover_alts" => array:2 [
                      0 => ""
                      1 => ""
                    ]
                    "field_covers" => array:2 [
                      0 => array:4 [
                        "path" => "/media/fizika_09/gendenshtejn-u/covers/cover1.webp?ts=1759256052"
                        "alt" => ""
                        "width" => "1863"
                        "height" => "2813"
                      ]
                      1 => array:4 [
                        "path" => "/media/fizika_09/gendenshtejn-u/covers/cover2.webp?ts=1759256052"
                        "alt" => ""
                        "width" => "1863"
                        "height" => "2809"
                      ]
                    ]
                    "field_popular_book" => "0"
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1222}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1223}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1224}
                    "field_url" => "/9-klass/fizika/gendenshtejn-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1225}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [
                      "class" => 380
                      "subject" => 556
                      "class_subject" => 493
                    ]
                  ]
                  #changes: []
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                  #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 {#1227
              #items: []
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 1433206
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => null
            "field_branch_order" => "1"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1197}
            "field_page_start" => "6"
            "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 {#1229}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1227}
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
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          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        1 => App\Models\Branch {#1228
          #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" => 1433207
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Механические явления"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1230
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "6"
            "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 {#1231
              #items: array:1 [
                0 => App\Models\Book {#1196}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1232
              #items: array:1 [
                0 => App\Models\Branch {#1034}
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 1433207
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Механические явления"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1230}
            "field_page_start" => "6"
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            "field_display_branch_in_title" => "1"
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            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1231}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1232}
          ]
          #changes: []
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          #attributeCastCache: []
          #dateFormat: null
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          #dispatchesEvents: []
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          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        2 => App\Models\Branch {#1233
          #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" => 1433231
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Механические колебания и волны"
            "field_branch_order" => "IV"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1237
              #items: array:1 [
                0 => App\Models\Term {#1234
                  #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 [ …6]
                    "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 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => null
                  ]
                  #changes: []
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                  #attributeCastCache: []
                  #dateFormat: null
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                  #dispatchesEvents: []
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                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "168"
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            "field_metatags_description" => null
            "field_h1" => null
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            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1236
              #items: array:1 [
                0 => App\Models\Book {#1196}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1310
              #items: array:1 [
                0 => App\Models\Branch {#1235
                  #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" => 1433207
                    "created_at" => "2026-04-10 13:58:26"
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                    "field_branch_order" => null
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1239 …2}
                    "field_page_start" => "6"
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                    "field_display_branch_page" => "1"
                    "field_branch_title_in_content" => "0"
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                    "field_metatags_description" => null
                    "field_h1" => null
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                    "field_description_bottom" => null
                    "field_branch_cover" => []
                    "field_branch_covers" => []
                    "book" => Illuminate\Database\Eloquent\Collection {#1238 …2}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1271 …2}
                  ]
                  #original: array:24 [
                    "id" => 1433207
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_display_title" => "Механические явления"
                    "field_branch_order" => null
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1239 …2}
                    "field_page_start" => "6"
                    "field_branch_display" => "0"
                    "field_branch_expanded" => "0"
                    "field_display_branch_in_title" => "1"
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                    "field_display_branch_page" => "1"
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                    "field_navigation_title" => null
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                    "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 {#1238 …2}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1271 …2}
                  ]
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                  #attributeCastCache: []
                  #dateFormat: null
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                  #touches: []
                  +timestamps: true
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                  #hidden: []
                  #visible: []
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                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
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          #original: array:24 [
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            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
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            "field_branch_order" => "IV"
            "field_url" => null
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          #dateFormat: null
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            0 => "*"
          ]
        }
        3 => App\Models\Branch {#1308
          #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" => 1433232
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Механические колебания"
            "field_branch_order" => "21"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1313
              #items: array:1 [
                0 => App\Models\Term {#1309
                  #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" => 32
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Параграф"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => "§"
                  ]
                  #original: array:7 [
                    "id" => 32
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Параграф"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => "§"
                  ]
                  #changes: []
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                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
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                  #dispatchesEvents: []
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                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "168"
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            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1312
              #items: array:1 [
                0 => App\Models\Book {#1196}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1321
              #items: array:1 [
                0 => App\Models\Branch {#1320
                  #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" => 1433231
                    "created_at" => "2026-04-10 13:58:26"
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                    "field_branch_order" => "IV"
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1322 …2}
                    "field_page_start" => "168"
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                    "field_display_branch_in_title" => "1"
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                    "field_branch_covers" => []
                    "book" => Illuminate\Database\Eloquent\Collection {#1323 …2}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1324 …2}
                  ]
                  #original: array:24 [
                    "id" => 1433231
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_display_title" => "Механические колебания и волны"
                    "field_branch_order" => "IV"
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1322 …2}
                    "field_page_start" => "168"
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                    "field_h1" => null
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                    "field_branch_covers" => []
                    "book" => Illuminate\Database\Eloquent\Collection {#1323 …2}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1324 …2}
                  ]
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                  #attributeCastCache: []
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                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
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            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Механические колебания"
            "field_branch_order" => "21"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1313}
            "field_page_start" => "168"
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            "field_h1" => null
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            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1312}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1321}
          ]
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          +timestamps: true
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          #visible: []
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          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "content" => Illuminate\Database\Eloquent\Collection {#1176
      #items: array:2 [
        0 => App\Models\Element {#1168
          #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" => 1696607
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1160
              #items: array:1 [
                0 => App\Models\Edition {#1166
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                    "created_at" => "2026-04-10 13:58:26"
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                    "title" => "Условие"
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                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1164 …2}
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                    "id" => 6168
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Условие"
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                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1164 …2}
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                    "field_solution_author" => "Автор"
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              "refs" => "1433866"
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            "text" => "<p><strong>38.</strong> Подвешенный на нити длиной 1 м небольшой груз массой 100 г совершает колебания. При наибольшем отклонении от положения равновесия груз поднимается на 2 см по сравнению с положением равновесия. Нулевому значению потенциальной энергии груза сопоставим положение равновесия. В начальный момент скорость груза равна нулю. Сопротивлением воздуха можно пренебречь.</p><p><strong>а)</strong> Чему равна потенциальная энергия груза в начальный момент?</p><p><strong>б)</strong> Чему равна кинетическая энергия груза через 0,5 с после начального момента?</p><p><strong>в)</strong> Чему равна скорость груза через 0,5 с после начального момента?</p><p>Положение равновесия</p>"
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              0 => array:5 [
                "name" => "38-1.jpg"
                "alt" => null
                "width" => "1576"
                "height" => 795
                "path" => "/media/fizika_09/gendenshtejn-u/0-21/38-1.webp?ts=1759348319"
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          #original: array:7 [
            "id" => 1696607
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1160}
            "task" => array:2 [
              "refs" => "1433866"
              "type" => "task"
            ]
            "text" => "<p><strong>38.</strong> Подвешенный на нити длиной 1 м небольшой груз массой 100 г совершает колебания. При наибольшем отклонении от положения равновесия груз поднимается на 2 см по сравнению с положением равновесия. Нулевому значению потенциальной энергии груза сопоставим положение равновесия. В начальный момент скорость груза равна нулю. Сопротивлением воздуха можно пренебречь.</p><p><strong>а)</strong> Чему равна потенциальная энергия груза в начальный момент?</p><p><strong>б)</strong> Чему равна кинетическая энергия груза через 0,5 с после начального момента?</p><p><strong>в)</strong> Чему равна скорость груза через 0,5 с после начального момента?</p><p>Положение равновесия</p>"
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                "width" => "1576"
                "height" => 795
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          #attributes: array:6 [
            "id" => 1780677
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1150
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                0 => App\Models\Edition {#1156
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
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                    "id" => 6515
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение"
                    "field_order" => "2"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1158 …2}
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                    "field_edition_type" => "solution"
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                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1155 …2}
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                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1158 …2}
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            "text" => "<p><strong>Дано:</strong></p><p>l = 1 м</p><p>m = 100 г = 0,1 кг</p><p>h<sub>max</sub> = 2 см = 0,02 м</p><p>t = 0,5 с</p><p>v<sub>0</sub> = 0 м/с (в начальный момент)</p><p>g ≈ 9,8 м/с²</p><p><strong>Найти:</strong></p><p>а) E<sub>p0</sub> - ?</p><p>б) E<sub>k</sub>(t) - ?</p><p>в) v(t) - ?</p><p><strong>Решение:</strong></p><p><strong>а) Чему равна потенциальная энергия груза в начальный момент?</strong></p><p>В начальный момент времени ($t=0$) груз находится в точке наибольшего отклонения от положения равновесия. По условию, в этот момент его скорость равна нулю, а высота над положением равновесия максимальна ($h_{max} = 0,02$ м). Потенциальная энергия тела, поднятого над нулевым уровнем, вычисляется по формуле:</p><p>$E_p = mgh$</p><p>Подставим значения для начального момента:</p><p>$E_{p0} = mgh_{max} = 0,1 \, \text{кг} \cdot 9,8 \, \text{м/с}^2 \cdot 0,02 \, \text{м} = 0,0196 \, \text{Дж}$</p><p><strong>Ответ:</strong> Потенциальная энергия груза в начальный момент равна 0,0196 Дж.</p><p>Поскольку сопротивлением воздуха можно пренебречь, полная механическая энергия маятника сохраняется. В начальный момент времени кинетическая энергия равна нулю ($E_{k0}=0$), поэтому полная механическая энергия системы равна начальной потенциальной энергии:</p><p>$E_{полная} = E_{p0} + E_{k0} = 0,0196 \, \text{Дж} + 0 = 0,0196 \, \text{Дж}$</p><p>Для определения состояния маятника через $t = 0,5$ с найдем период его колебаний. Период колебаний математического маятника определяется формулой:</p><p>$T = 2\pi\sqrt{\frac{l}{g}}$</p><p>$T = 2\pi\sqrt{\frac{1 \, \text{м}}{9,8 \, \text{м/с}^2}} \approx 6,283 \cdot 0,319 \, \text{с} \approx 2,007 \, \text{с}$</p><p>Маятник начинает движение из крайнего положения (максимального отклонения). Время, за которое он достигает положения равновесия, составляет одну четверть периода ($T/4$).</p><p>$t_{равн} = \frac{T}{4} \approx \frac{2,007 \, \text{с}}{4} \approx 0,502 \, \text{с}$</p><p>Заданный момент времени $t = 0,5$ с очень близок ко времени прохождения положения равновесия. Поэтому для решения задачи можно считать, что через 0,5 с груз находится в положении равновесия.</p><p><strong>б) Чему равна кинетическая энергия груза через 0,5 с после начального момента?</strong></p><p>В положении равновесия высота груза над нулевым уровнем равна нулю ($h=0$), следовательно, его потенциальная энергия в этот момент также равна нулю ($E_p(t) \approx 0$).</p><p>Согласно закону сохранения полной механической энергии:</p><p>$E_{полная} = E_p(t) + E_k(t)$</p><p>Отсюда находим кинетическую энергию в момент времени $t = 0,5$ с:</p><p>$E_k(t) = E_{полная} - E_p(t) \approx 0,0196 \, \text{Дж} - 0 = 0,0196 \, \text{Дж}$</p><p><strong>Ответ:</strong> Кинетическая энергия груза через 0,5 с приблизительно равна 0,0196 Дж.</p><p><strong>в) Чему равна скорость груза через 0,5 с после начального момента?</strong></p><p>Зная кинетическую энергию груза, можно найти его скорость из формулы:</p><p>$E_k(t) = \frac{mv(t)^2}{2}$</p><p>Выразим из этой формулы скорость $v(t)$:</p><p>$v(t) = \sqrt{\frac{2E_k(t)}{m}}$</p><p>Подставим числовые значения:</p><p>$v(t) \approx \sqrt{\frac{2 \cdot 0,0196 \, \text{Дж}}{0,1 \, \text{кг}}} = \sqrt{0,392} \, \text{м/с} \approx 0,626 \, \text{м/с}$</p><p><strong>Ответ:</strong> Скорость груза через 0,5 с приблизительно равна 0,626 м/с.</p>"
          ]
          #original: array:6 [
            "id" => 1780677
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1150}
            "task" => array:2 [
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              "type" => "task"
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            "text" => "<p><strong>Дано:</strong></p><p>l = 1 м</p><p>m = 100 г = 0,1 кг</p><p>h<sub>max</sub> = 2 см = 0,02 м</p><p>t = 0,5 с</p><p>v<sub>0</sub> = 0 м/с (в начальный момент)</p><p>g ≈ 9,8 м/с²</p><p><strong>Найти:</strong></p><p>а) E<sub>p0</sub> - ?</p><p>б) E<sub>k</sub>(t) - ?</p><p>в) v(t) - ?</p><p><strong>Решение:</strong></p><p><strong>а) Чему равна потенциальная энергия груза в начальный момент?</strong></p><p>В начальный момент времени ($t=0$) груз находится в точке наибольшего отклонения от положения равновесия. По условию, в этот момент его скорость равна нулю, а высота над положением равновесия максимальна ($h_{max} = 0,02$ м). Потенциальная энергия тела, поднятого над нулевым уровнем, вычисляется по формуле:</p><p>$E_p = mgh$</p><p>Подставим значения для начального момента:</p><p>$E_{p0} = mgh_{max} = 0,1 \, \text{кг} \cdot 9,8 \, \text{м/с}^2 \cdot 0,02 \, \text{м} = 0,0196 \, \text{Дж}$</p><p><strong>Ответ:</strong> Потенциальная энергия груза в начальный момент равна 0,0196 Дж.</p><p>Поскольку сопротивлением воздуха можно пренебречь, полная механическая энергия маятника сохраняется. В начальный момент времени кинетическая энергия равна нулю ($E_{k0}=0$), поэтому полная механическая энергия системы равна начальной потенциальной энергии:</p><p>$E_{полная} = E_{p0} + E_{k0} = 0,0196 \, \text{Дж} + 0 = 0,0196 \, \text{Дж}$</p><p>Для определения состояния маятника через $t = 0,5$ с найдем период его колебаний. Период колебаний математического маятника определяется формулой:</p><p>$T = 2\pi\sqrt{\frac{l}{g}}$</p><p>$T = 2\pi\sqrt{\frac{1 \, \text{м}}{9,8 \, \text{м/с}^2}} \approx 6,283 \cdot 0,319 \, \text{с} \approx 2,007 \, \text{с}$</p><p>Маятник начинает движение из крайнего положения (максимального отклонения). Время, за которое он достигает положения равновесия, составляет одну четверть периода ($T/4$).</p><p>$t_{равн} = \frac{T}{4} \approx \frac{2,007 \, \text{с}}{4} \approx 0,502 \, \text{с}$</p><p>Заданный момент времени $t = 0,5$ с очень близок ко времени прохождения положения равновесия. Поэтому для решения задачи можно считать, что через 0,5 с груз находится в положении равновесия.</p><p><strong>б) Чему равна кинетическая энергия груза через 0,5 с после начального момента?</strong></p><p>В положении равновесия высота груза над нулевым уровнем равна нулю ($h=0$), следовательно, его потенциальная энергия в этот момент также равна нулю ($E_p(t) \approx 0$).</p><p>Согласно закону сохранения полной механической энергии:</p><p>$E_{полная} = E_p(t) + E_k(t)$</p><p>Отсюда находим кинетическую энергию в момент времени $t = 0,5$ с:</p><p>$E_k(t) = E_{полная} - E_p(t) \approx 0,0196 \, \text{Дж} - 0 = 0,0196 \, \text{Дж}$</p><p><strong>Ответ:</strong> Кинетическая энергия груза через 0,5 с приблизительно равна 0,0196 Дж.</p><p><strong>в) Чему равна скорость груза через 0,5 с после начального момента?</strong></p><p>Зная кинетическую энергию груза, можно найти его скорость из формулы:</p><p>$E_k(t) = \frac{mv(t)^2}{2}$</p><p>Выразим из этой формулы скорость $v(t)$:</p><p>$v(t) = \sqrt{\frac{2E_k(t)}{m}}$</p><p>Подставим числовые значения:</p><p>$v(t) \approx \sqrt{\frac{2 \cdot 0,0196 \, \text{Дж}}{0,1 \, \text{кг}}} = \sqrt{0,392} \, \text{м/с} \approx 0,626 \, \text{м/с}$</p><p><strong>Ответ:</strong> Скорость груза через 0,5 с приблизительно равна 0,626 м/с.</p>"
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      #items: array:1 [
        0 => App\Models\Book {#1196}
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      #escapeWhenCastingToString: false
    }
    "page" => Illuminate\Database\Eloquent\Collection {#1145
      #items: array:1 [
        0 => App\Models\BookPage {#1148
          #connection: "mysql"
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            "field_display_title" => "179"
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            "content" => Illuminate\Database\Eloquent\Collection {#1147
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№38 (с. 179)
Условие. №38 (с. 179)
скриншот условия
Физика, 9 класс Учебник, авторы: Генденштейн Лев Элевич, Булатова Альбина Александрова, Корнильев Игорь Николаевич, Кошкина Анжелика Васильевна, издательство Бином, Москва, 2016, бирюзового цвета, Часть 1, страница 179, номер 38, Условие

38. Подвешенный на нити длиной 1 м небольшой груз массой 100 г совершает колебания. При наибольшем отклонении от положения равновесия груз поднимается на 2 см по сравнению с положением равновесия. Нулевому значению потенциальной энергии груза сопоставим положение равновесия. В начальный момент скорость груза равна нулю. Сопротивлением воздуха можно пренебречь.

а) Чему равна потенциальная энергия груза в начальный момент?

б) Чему равна кинетическая энергия груза через 0,5 с после начального момента?

в) Чему равна скорость груза через 0,5 с после начального момента?

Положение равновесия

Решение. №38 (с. 179)

Дано:

l = 1 м

m = 100 г = 0,1 кг

hmax = 2 см = 0,02 м

t = 0,5 с

v0 = 0 м/с (в начальный момент)

g ≈ 9,8 м/с²

Найти:

а) Ep0 - ?

б) Ek(t) - ?

в) v(t) - ?

Решение:

а) Чему равна потенциальная энергия груза в начальный момент?

В начальный момент времени ($t=0$) груз находится в точке наибольшего отклонения от положения равновесия. По условию, в этот момент его скорость равна нулю, а высота над положением равновесия максимальна ($h_{max} = 0,02$ м). Потенциальная энергия тела, поднятого над нулевым уровнем, вычисляется по формуле:

$E_p = mgh$

Подставим значения для начального момента:

$E_{p0} = mgh_{max} = 0,1 \, \text{кг} \cdot 9,8 \, \text{м/с}^2 \cdot 0,02 \, \text{м} = 0,0196 \, \text{Дж}$

Ответ: Потенциальная энергия груза в начальный момент равна 0,0196 Дж.

Поскольку сопротивлением воздуха можно пренебречь, полная механическая энергия маятника сохраняется. В начальный момент времени кинетическая энергия равна нулю ($E_{k0}=0$), поэтому полная механическая энергия системы равна начальной потенциальной энергии:

$E_{полная} = E_{p0} + E_{k0} = 0,0196 \, \text{Дж} + 0 = 0,0196 \, \text{Дж}$

Для определения состояния маятника через $t = 0,5$ с найдем период его колебаний. Период колебаний математического маятника определяется формулой:

$T = 2\pi\sqrt{\frac{l}{g}}$

$T = 2\pi\sqrt{\frac{1 \, \text{м}}{9,8 \, \text{м/с}^2}} \approx 6,283 \cdot 0,319 \, \text{с} \approx 2,007 \, \text{с}$

Маятник начинает движение из крайнего положения (максимального отклонения). Время, за которое он достигает положения равновесия, составляет одну четверть периода ($T/4$).

$t_{равн} = \frac{T}{4} \approx \frac{2,007 \, \text{с}}{4} \approx 0,502 \, \text{с}$

Заданный момент времени $t = 0,5$ с очень близок ко времени прохождения положения равновесия. Поэтому для решения задачи можно считать, что через 0,5 с груз находится в положении равновесия.

б) Чему равна кинетическая энергия груза через 0,5 с после начального момента?

В положении равновесия высота груза над нулевым уровнем равна нулю ($h=0$), следовательно, его потенциальная энергия в этот момент также равна нулю ($E_p(t) \approx 0$).

Согласно закону сохранения полной механической энергии:

$E_{полная} = E_p(t) + E_k(t)$

Отсюда находим кинетическую энергию в момент времени $t = 0,5$ с:

$E_k(t) = E_{полная} - E_p(t) \approx 0,0196 \, \text{Дж} - 0 = 0,0196 \, \text{Дж}$

Ответ: Кинетическая энергия груза через 0,5 с приблизительно равна 0,0196 Дж.

в) Чему равна скорость груза через 0,5 с после начального момента?

Зная кинетическую энергию груза, можно найти его скорость из формулы:

$E_k(t) = \frac{mv(t)^2}{2}$

Выразим из этой формулы скорость $v(t)$:

$v(t) = \sqrt{\frac{2E_k(t)}{m}}$

Подставим числовые значения:

$v(t) \approx \sqrt{\frac{2 \cdot 0,0196 \, \text{Дж}}{0,1 \, \text{кг}}} = \sqrt{0,392} \, \text{м/с} \approx 0,626 \, \text{м/с}$

Ответ: Скорость груза через 0,5 с приблизительно равна 0,626 м/с.

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