Номер 4.16, страница 22 - гдз по физике 8-11 класс учебник, задачник Гельфгат, Генденштейн

Физика, 8-11 класс Учебник, задачник, авторы: Гельфгат Илья Маркович, Генденштейн Лев Элевич, Кирик Леонид Анатольевич, издательство Илекса, Москва, 2005

Авторы: Гельфгат И. М., Генденштейн Л. Э., Кирик Л. А.

Тип: Учебник, задачник

Издательство: Илекса

Год издания: 2005 - 2026

Цвет обложки: синий мужчина в красном, летит на черном шаре

ISBN: 978-5-89237-332-6

Задачи. Механика. 4. Импульс, работа, энергия. Законы сохранения - номер 4.16, страница 22.

App\Models\Task {#1030 // resources/views/models/task/default.blade.php
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                            "field_translit" => "odinadcatyj"
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                            "id" => 5460
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "11"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "odinadcatyj"
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                      ]
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                    }
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1174
                      #items: array:1 [
                        0 => App\Models\Term {#1175
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
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                          +exists: true
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                          #attributes: array:6 [
                            "id" => 5158
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Илекса"
                            "field_cases" => null
                            "field_translit" => "ileksa"
                          ]
                          #original: array:6 [
                            "id" => 5158
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Илекса"
                            "field_cases" => null
                            "field_translit" => "ileksa"
                          ]
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                        }
                      ]
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                    }
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1176
                      #items: array:3 [
                        0 => App\Models\Term {#1177
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
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                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:12 [
                            "id" => 4102
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Гельфгат"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Илья"
                            "field_patronymic" => "Маркович"
                            "field_surname_rp" => null
                          ]
                          #original: array:12 [
                            "id" => 4102
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Гельфгат"
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                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Илья"
                            "field_patronymic" => "Маркович"
                            "field_surname_rp" => null
                          ]
                          #changes: []
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                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
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                          #relations: []
                          #touches: []
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                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                        1 => App\Models\Term {#1178
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:12 [
                            "id" => 4104
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Генденштейн"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Лев"
                            "field_patronymic" => "Элевич"
                            "field_surname_rp" => "Генденштейна"
                          ]
                          #original: array:12 [
                            "id" => 4104
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Генденштейн"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Лев"
                            "field_patronymic" => "Элевич"
                            "field_surname_rp" => "Генденштейна"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                        2 => App\Models\Term {#1179
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:12 [
                            "id" => 4583
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Кирик"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Леонид"
                            "field_patronymic" => "Анатольевич"
                            "field_surname_rp" => null
                          ]
                          #original: array:12 [
                            "id" => 4583
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Кирик"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Леонид"
                            "field_patronymic" => "Анатольевич"
                            "field_surname_rp" => null
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
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                          #relations: []
                          #touches: []
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                          #hidden: []
                          #visible: []
                          #fillable: []
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                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1180
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1181
                      #items: array:1 [
                        0 => App\Models\Term {#1182
                          #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" => 6673
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Учебник, задачник"
                            "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, zadachnik"
                          ]
                          #original: array:10 [
                            "id" => 6673
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Учебник, задачник"
                            "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, zadachnik"
                          ]
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                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
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                          #relations: []
                          #touches: []
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                          #hidden: []
                          #visible: []
                          #fillable: []
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                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1183
                      #items: array:1 [
                        0 => App\Models\Term {#1184
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
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                          #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: []
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                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
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                          #dispatchesEvents: []
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                          #touches: []
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                          #hidden: []
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                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1185
                      #items: array:1 [
                        0 => App\Models\Term {#1186
                          #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"
                          ]
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                        }
                      ]
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                    }
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1187
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1188
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1189
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1190
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_publication_number" => "6"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1191
                      #items: array:1 [
                        0 => App\Models\Term {#1192
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
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                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 35
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "исправленное"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "ispravlennoe"
                          ]
                          #original: array:6 [
                            "id" => 35
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "исправленное"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "ispravlennoe"
                          ]
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                          ]
                        }
                      ]
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                    }
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1193
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "мужчина в красном, летит на черном шаре"
                    "field_publication_year" => "2005"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебное издание"
                    "field_allowed" => null
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                    "field_link_to_source" => null
                    "field_tasks_count" => "1001"
                    "field_priority" => null
                    "field_default_folder" => "/fizika_08/gelfgat-u/"
                    "field_isbn" => "978-5-89237-332-6"
                    "field_cover" => array:1 [
                      0 => "/media/fizika_08/gelfgat-u/covers/cover1.webp?ts=1755898771"
                    ]
                    "field_cover_alts" => array:1 [
                      0 => ""
                    ]
                    "field_covers" => array:1 [
                      0 => array:4 [
                        "path" => "/media/fizika_08/gelfgat-u/covers/cover1.webp?ts=1755898771"
                        "alt" => ""
                        "width" => "1813"
                        "height" => "2441"
                      ]
                    ]
                    "field_popular_book" => "0"
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                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1195
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1196
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_url" => "/8-klass/fizika/ileksa-gelfgat-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1197
                      #items: array:1 [
                        0 => App\Models\Term {#1198
                          #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 [ …6]
                            "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 [ …6]
                            "field_translit" => "siniy"
                          ]
                          #changes: []
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                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
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                          #relations: []
                          #touches: []
                          +timestamps: true
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                          #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" => 5401
                    "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 {#1168}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1169}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1174}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1176}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1180}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1181}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1183}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1185}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1187}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1188}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1189}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1190}
                    "field_publication_number" => "6"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1191}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1193}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "мужчина в красном, летит на черном шаре"
                    "field_publication_year" => "2005"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебное издание"
                    "field_allowed" => null
                    "field_reserve_field" => null
                    "field_link_to_source" => null
                    "field_tasks_count" => "1001"
                    "field_priority" => null
                    "field_default_folder" => "/fizika_08/gelfgat-u/"
                    "field_isbn" => "978-5-89237-332-6"
                    "field_cover" => array:1 [
                      0 => "/media/fizika_08/gelfgat-u/covers/cover1.webp?ts=1755898771"
                    ]
                    "field_cover_alts" => array:1 [
                      0 => ""
                    ]
                    "field_covers" => array:1 [
                      0 => array:4 [
                        "path" => "/media/fizika_08/gelfgat-u/covers/cover1.webp?ts=1755898771"
                        "alt" => ""
                        "width" => "1813"
                        "height" => "2441"
                      ]
                    ]
                    "field_popular_book" => "0"
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1194}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1195}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1196}
                    "field_url" => "/8-klass/fizika/ileksa-gelfgat-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1197}
                    "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
                    ]
                  ]
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                  #attributeCastCache: []
                  #dateFormat: null
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                  #touches: []
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                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1199
              #items: []
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 1287866
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Задачи"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1165}
            "field_page_start" => "5"
            "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 {#1201}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1199}
          ]
          #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 => "*"
          ]
        }
        1 => App\Models\Branch {#1200
          #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" => 1287867
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Механика"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1202
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "5"
            "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 {#1203
              #items: array:1 [
                0 => App\Models\Book {#1166}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1204
              #items: array:1 [
                0 => App\Models\Branch {#1034}
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 1287867
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Механика"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1202}
            "field_page_start" => "5"
            "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
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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 {#1203}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1204}
          ]
          #changes: []
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          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
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          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        2 => App\Models\Branch {#1205
          #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" => 1287871
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "4. Импульс, работа, энергия. Законы сохранения"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1206
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "20"
            "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 {#1207
              #items: array:1 [
                0 => App\Models\Book {#1166}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1251
              #items: array:1 [
                0 => App\Models\Branch {#1208
                  #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" => 1287867
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_display_title" => "Механика"
                    "field_branch_order" => null
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1210 …2}
                    "field_page_start" => "5"
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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 {#1209 …2}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1244 …2}
                  ]
                  #original: array:24 [
                    "id" => 1287867
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_display_title" => "Механика"
                    "field_branch_order" => null
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1210 …2}
                    "field_page_start" => "5"
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                    "field_h1" => null
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                    "field_description_bottom" => null
                    "field_branch_cover" => []
                    "field_branch_covers" => []
                    "book" => Illuminate\Database\Eloquent\Collection {#1209 …2}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1244 …2}
                  ]
                  #changes: []
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                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
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                  +timestamps: true
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                  #visible: []
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                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 1287871
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "4. Импульс, работа, энергия. Законы сохранения"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1206}
            "field_page_start" => "20"
            "field_branch_display" => "0"
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            "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
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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 {#1207}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1251}
          ]
          #changes: []
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          #attributeCastCache: []
          #dateFormat: null
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          #touches: []
          +timestamps: true
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          #hidden: []
          #visible: []
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          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "content" => Illuminate\Database\Eloquent\Collection {#1148
      #items: array:3 [
        0 => App\Models\Element {#1143
          #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" => 1477806
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1135
              #items: array:1 [
                0 => App\Models\Edition {#1142
                  #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" => 5410
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Условие"
                    "field_order" => "1"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1141 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "text, image"
                    "field_page_content_mode" => "image"
                    "field_content_text_checked" => null
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Автор"
                    "field_moderator" => "stas"
                    "field_edition_type" => "statement"
                    "field_root_dir" => "0-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1139 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1138 …2}
                    "field_process_formula" => "katex"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1137 …2}
                    "field_content_source" => null
                  ]
                  #original: array:21 [
                    "id" => 5410
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Условие"
                    "field_order" => "1"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1141 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "text, image"
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                    "field_content_text_checked" => null
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Автор"
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                    "field_edition_type" => "statement"
                    "field_root_dir" => "0-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1139 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1138 …2}
                    "field_process_formula" => "katex"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1137 …2}
                    "field_content_source" => null
                  ]
                  #changes: []
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                  #attributeCastCache: []
                  #dateFormat: null
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                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
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                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "1288031"
              "type" => "task"
            ]
            "text" => "<p><strong>4.16.</strong> Автомобиль массой $M = 2 \text{ т}$ разгоняется с места, въезжая на гору с уклоном 0,02. Коэффициент сопротивления $\mu = 0,05$. Автомобиль набирает скорость $v = 97,2 \text{ км/ч}$ на участке длиной $s = 100 \text{ м}$. Какую среднюю мощность $P_{\text{ср}}$ развивает двигатель?</p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "16-1.jpg"
                "alt" => null
                "width" => "1446"
                "height" => 311
                "path" => "/media/fizika_08/gelfgat-u/0-04/16-1.webp?ts=1756049698"
              ]
            ]
          ]
          #original: array:7 [
            "id" => 1477806
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1135}
            "task" => array:2 [
              "refs" => "1288031"
              "type" => "task"
            ]
            "text" => "<p><strong>4.16.</strong> Автомобиль массой $M = 2 \text{ т}$ разгоняется с места, въезжая на гору с уклоном 0,02. Коэффициент сопротивления $\mu = 0,05$. Автомобиль набирает скорость $v = 97,2 \text{ км/ч}$ на участке длиной $s = 100 \text{ м}$. Какую среднюю мощность $P_{\text{ср}}$ развивает двигатель?</p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "16-1.jpg"
                "alt" => null
                "width" => "1446"
                "height" => 311
                "path" => "/media/fizika_08/gelfgat-u/0-04/16-1.webp?ts=1756049698"
              ]
            ]
          ]
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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 => "*"
          ]
        }
        1 => App\Models\Element {#1136
          #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" => 1478191
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1127
              #items: array:1 [
                0 => App\Models\Edition {#1134
                  #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" => 5411
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение"
                    "field_order" => "2"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1133 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "image"
                    "field_page_content_mode" => ""
                    "field_content_text_checked" => "0"
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Автор"
                    "field_moderator" => "stas"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "1-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1130 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1131 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1129 …2}
                    "field_content_source" => null
                  ]
                  #original: array:21 [
                    "id" => 5411
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение"
                    "field_order" => "2"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1133 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "image"
                    "field_page_content_mode" => ""
                    "field_content_text_checked" => "0"
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Автор"
                    "field_moderator" => "stas"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "1-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1130 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1131 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1129 …2}
                    "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" => "1288031"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "16-1.jpg"
                "alt" => null
                "width" => "1422"
                "height" => 798
                "path" => "/media/fizika_08/gelfgat-u/1-04/16-1.webp?ts=1756049759"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 1478191
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1127}
            "task" => array:2 [
              "refs" => "1288031"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "16-1.jpg"
                "alt" => null
                "width" => "1422"
                "height" => 798
                "path" => "/media/fizika_08/gelfgat-u/1-04/16-1.webp?ts=1756049759"
              ]
            ]
          ]
          #changes: []
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          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
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          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        2 => App\Models\Element {#1125
          #connection: "mysql"
          #table: "elements"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
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            "text" => "<p><strong>Дано:</strong></p><p>$M = 2 \text{ т}$</p><p>$v_0 = 0 \text{ м/с}$ (разгоняется с места)</p><p>$k = 0,02$ (уклон)</p><p>$\mu = 0,05$</p><p>$v = 97,2 \text{ км/ч}$</p><p>$s = 100 \text{ м}$</p><p><br><em>Перевод в систему СИ:</em></p><p>$M = 2 \cdot 1000 = 2000 \text{ кг}$</p><p>$v = 97,2 \cdot \frac{1000}{3600} = 27 \text{ м/с}$</p><p><strong>Найти:</strong></p><p>$P_{ср}$</p><p><strong>Решение:</strong></p><p>Работу, совершаемую двигателем, можно найти с помощью теоремы об изменении кинетической энергии. Изменение кинетической энергии автомобиля равно сумме работ всех сил, действующих на него:</p><p>$\Delta E_к = A_{тяг} + A_g + A_{сопр}$</p><p>где $\Delta E_к$ — изменение кинетической энергии, $A_{тяг}$ — работа силы тяги двигателя, $A_g$ — работа силы тяжести, $A_{сопр}$ — работа силы сопротивления.</p><p><strong>1.</strong> Изменение кинетической энергии:</p><p>$\Delta E_к = E_{к2} - E_{к1} = \frac{Mv^2}{2} - \frac{Mv_0^2}{2}$</p><p>Так как автомобиль начинает движение с места ($v_0 = 0$), то:</p><p>$\Delta E_к = \frac{Mv^2}{2} = \frac{2000 \text{ кг} \cdot (27 \text{ м/с})^2}{2} = 1000 \cdot 729 = 729000 \text{ Дж}$</p><p><strong>2.</strong> Работа силы тяжести. При движении на гору сила тяжести совершает отрицательную работу.</p><p>$A_g = -Mgh$</p><p>Высоту подъема $\text{h}$ можно найти через уклон $\text{k}$. Для малых углов уклон $k = \tan\alpha \approx \sin\alpha$. Тогда $h = s \cdot \sin\alpha \approx s \cdot k$.</p><p>$A_g = -Mgsk = -2000 \text{ кг} \cdot 9,8 \text{ м/с}^2 \cdot 100 \text{ м} \cdot 0,02 = -39200 \text{ Дж}$</p><p><strong>3.</strong> Работа силы сопротивления. Сила сопротивления направлена против движения, поэтому её работа отрицательна.</p><p>$A_{сопр} = -F_{сопр} \cdot s$</p><p>Сила сопротивления $F_{сопр}$ пропорциональна силе нормальной реакции $\text{N}$: $F_{сопр} = \mu N$. На наклонной плоскости $N = Mg\cos\alpha$. Для малого уклона $\cos\alpha \approx 1$, поэтому $F_{сопр} \approx \mu Mg$.</p><p>$A_{сопр} = -\mu Mgs = -0,05 \cdot 2000 \text{ кг} \cdot 9,8 \text{ м/с}^2 \cdot 100 \text{ м} = -98000 \text{ Дж}$</p><p><strong>4.</strong> Работа силы тяги двигателя $A_{тяг}$:</p><p>$A_{тяг} = \Delta E_к - A_g - A_{сопр} = 729000 \text{ Дж} - (-39200 \text{ Дж}) - (-98000 \text{ Дж}) = 729000 + 39200 + 98000 = 866200 \text{ Дж}$</p><p><strong>5.</strong> Средняя мощность $P_{ср}$ — это отношение работы к времени, за которое она была совершена:</p><p>$P_{ср} = \frac{A_{тяг}}{t}$</p><p>Время движения $\text{t}$ можно найти, предположив, что движение было равноускоренным. Тогда путь $\text{s}$ равен:</p><p>$s = \frac{v_0 + v}{2} \cdot t = \frac{v}{2} \cdot t$</p><p>Отсюда время:</p><p>$t = \frac{2s}{v} = \frac{2 \cdot 100 \text{ м}}{27 \text{ м/с}} \approx 7,41 \text{ с}$</p><p><strong>6.</strong> Вычисляем среднюю мощность:</p><p>$P_{ср} = \frac{866200 \text{ Дж}}{7,41 \text{ с}} \approx 116937 \text{ Вт}$</p><p>Переведем в киловатты: $116937 \text{ Вт} \approx 117 \text{ кВт}$.</p><p><strong>Ответ:</strong> средняя мощность, развиваемая двигателем, составляет примерно $117 \text{ кВт}$.</p>"
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            "text" => "<p><strong>Дано:</strong></p><p>$M = 2 \text{ т}$</p><p>$v_0 = 0 \text{ м/с}$ (разгоняется с места)</p><p>$k = 0,02$ (уклон)</p><p>$\mu = 0,05$</p><p>$v = 97,2 \text{ км/ч}$</p><p>$s = 100 \text{ м}$</p><p><br><em>Перевод в систему СИ:</em></p><p>$M = 2 \cdot 1000 = 2000 \text{ кг}$</p><p>$v = 97,2 \cdot \frac{1000}{3600} = 27 \text{ м/с}$</p><p><strong>Найти:</strong></p><p>$P_{ср}$</p><p><strong>Решение:</strong></p><p>Работу, совершаемую двигателем, можно найти с помощью теоремы об изменении кинетической энергии. Изменение кинетической энергии автомобиля равно сумме работ всех сил, действующих на него:</p><p>$\Delta E_к = A_{тяг} + A_g + A_{сопр}$</p><p>где $\Delta E_к$ — изменение кинетической энергии, $A_{тяг}$ — работа силы тяги двигателя, $A_g$ — работа силы тяжести, $A_{сопр}$ — работа силы сопротивления.</p><p><strong>1.</strong> Изменение кинетической энергии:</p><p>$\Delta E_к = E_{к2} - E_{к1} = \frac{Mv^2}{2} - \frac{Mv_0^2}{2}$</p><p>Так как автомобиль начинает движение с места ($v_0 = 0$), то:</p><p>$\Delta E_к = \frac{Mv^2}{2} = \frac{2000 \text{ кг} \cdot (27 \text{ м/с})^2}{2} = 1000 \cdot 729 = 729000 \text{ Дж}$</p><p><strong>2.</strong> Работа силы тяжести. При движении на гору сила тяжести совершает отрицательную работу.</p><p>$A_g = -Mgh$</p><p>Высоту подъема $\text{h}$ можно найти через уклон $\text{k}$. Для малых углов уклон $k = \tan\alpha \approx \sin\alpha$. Тогда $h = s \cdot \sin\alpha \approx s \cdot k$.</p><p>$A_g = -Mgsk = -2000 \text{ кг} \cdot 9,8 \text{ м/с}^2 \cdot 100 \text{ м} \cdot 0,02 = -39200 \text{ Дж}$</p><p><strong>3.</strong> Работа силы сопротивления. Сила сопротивления направлена против движения, поэтому её работа отрицательна.</p><p>$A_{сопр} = -F_{сопр} \cdot s$</p><p>Сила сопротивления $F_{сопр}$ пропорциональна силе нормальной реакции $\text{N}$: $F_{сопр} = \mu N$. На наклонной плоскости $N = Mg\cos\alpha$. Для малого уклона $\cos\alpha \approx 1$, поэтому $F_{сопр} \approx \mu Mg$.</p><p>$A_{сопр} = -\mu Mgs = -0,05 \cdot 2000 \text{ кг} \cdot 9,8 \text{ м/с}^2 \cdot 100 \text{ м} = -98000 \text{ Дж}$</p><p><strong>4.</strong> Работа силы тяги двигателя $A_{тяг}$:</p><p>$A_{тяг} = \Delta E_к - A_g - A_{сопр} = 729000 \text{ Дж} - (-39200 \text{ Дж}) - (-98000 \text{ Дж}) = 729000 + 39200 + 98000 = 866200 \text{ Дж}$</p><p><strong>5.</strong> Средняя мощность $P_{ср}$ — это отношение работы к времени, за которое она была совершена:</p><p>$P_{ср} = \frac{A_{тяг}}{t}$</p><p>Время движения $\text{t}$ можно найти, предположив, что движение было равноускоренным. Тогда путь $\text{s}$ равен:</p><p>$s = \frac{v_0 + v}{2} \cdot t = \frac{v}{2} \cdot t$</p><p>Отсюда время:</p><p>$t = \frac{2s}{v} = \frac{2 \cdot 100 \text{ м}}{27 \text{ м/с}} \approx 7,41 \text{ с}$</p><p><strong>6.</strong> Вычисляем среднюю мощность:</p><p>$P_{ср} = \frac{866200 \text{ Дж}}{7,41 \text{ с}} \approx 116937 \text{ Вт}$</p><p>Переведем в киловатты: $116937 \text{ Вт} \approx 117 \text{ кВт}$.</p><p><strong>Ответ:</strong> средняя мощность, развиваемая двигателем, составляет примерно $117 \text{ кВт}$.</p>"
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№4.16 (с. 22)
Условие. №4.16 (с. 22)
скриншот условия
Физика, 8-11 класс Учебник, задачник, авторы: Гельфгат Илья Маркович, Генденштейн Лев Элевич, Кирик Леонид Анатольевич, издательство Илекса, Москва, 2005, страница 22, номер 4.16, Условие

4.16. Автомобиль массой $M = 2 \text{ т}$ разгоняется с места, въезжая на гору с уклоном 0,02. Коэффициент сопротивления $\mu = 0,05$. Автомобиль набирает скорость $v = 97,2 \text{ км/ч}$ на участке длиной $s = 100 \text{ м}$. Какую среднюю мощность $P_{\text{ср}}$ развивает двигатель?

Решение. №4.16 (с. 22)
Физика, 8-11 класс Учебник, задачник, авторы: Гельфгат Илья Маркович, Генденштейн Лев Элевич, Кирик Леонид Анатольевич, издательство Илекса, Москва, 2005, страница 22, номер 4.16, Решение
Решение 2. №4.16 (с. 22)

Дано:

$M = 2 \text{ т}$

$v_0 = 0 \text{ м/с}$ (разгоняется с места)

$k = 0,02$ (уклон)

$\mu = 0,05$

$v = 97,2 \text{ км/ч}$

$s = 100 \text{ м}$


Перевод в систему СИ:

$M = 2 \cdot 1000 = 2000 \text{ кг}$

$v = 97,2 \cdot \frac{1000}{3600} = 27 \text{ м/с}$

Найти:

$P_{ср}$

Решение:

Работу, совершаемую двигателем, можно найти с помощью теоремы об изменении кинетической энергии. Изменение кинетической энергии автомобиля равно сумме работ всех сил, действующих на него:

$\Delta E_к = A_{тяг} + A_g + A_{сопр}$

где $\Delta E_к$ — изменение кинетической энергии, $A_{тяг}$ — работа силы тяги двигателя, $A_g$ — работа силы тяжести, $A_{сопр}$ — работа силы сопротивления.

1. Изменение кинетической энергии:

$\Delta E_к = E_{к2} - E_{к1} = \frac{Mv^2}{2} - \frac{Mv_0^2}{2}$

Так как автомобиль начинает движение с места ($v_0 = 0$), то:

$\Delta E_к = \frac{Mv^2}{2} = \frac{2000 \text{ кг} \cdot (27 \text{ м/с})^2}{2} = 1000 \cdot 729 = 729000 \text{ Дж}$

2. Работа силы тяжести. При движении на гору сила тяжести совершает отрицательную работу.

$A_g = -Mgh$

Высоту подъема $\text{h}$ можно найти через уклон $\text{k}$. Для малых углов уклон $k = \tan\alpha \approx \sin\alpha$. Тогда $h = s \cdot \sin\alpha \approx s \cdot k$.

$A_g = -Mgsk = -2000 \text{ кг} \cdot 9,8 \text{ м/с}^2 \cdot 100 \text{ м} \cdot 0,02 = -39200 \text{ Дж}$

3. Работа силы сопротивления. Сила сопротивления направлена против движения, поэтому её работа отрицательна.

$A_{сопр} = -F_{сопр} \cdot s$

Сила сопротивления $F_{сопр}$ пропорциональна силе нормальной реакции $\text{N}$: $F_{сопр} = \mu N$. На наклонной плоскости $N = Mg\cos\alpha$. Для малого уклона $\cos\alpha \approx 1$, поэтому $F_{сопр} \approx \mu Mg$.

$A_{сопр} = -\mu Mgs = -0,05 \cdot 2000 \text{ кг} \cdot 9,8 \text{ м/с}^2 \cdot 100 \text{ м} = -98000 \text{ Дж}$

4. Работа силы тяги двигателя $A_{тяг}$:

$A_{тяг} = \Delta E_к - A_g - A_{сопр} = 729000 \text{ Дж} - (-39200 \text{ Дж}) - (-98000 \text{ Дж}) = 729000 + 39200 + 98000 = 866200 \text{ Дж}$

5. Средняя мощность $P_{ср}$ — это отношение работы к времени, за которое она была совершена:

$P_{ср} = \frac{A_{тяг}}{t}$

Время движения $\text{t}$ можно найти, предположив, что движение было равноускоренным. Тогда путь $\text{s}$ равен:

$s = \frac{v_0 + v}{2} \cdot t = \frac{v}{2} \cdot t$

Отсюда время:

$t = \frac{2s}{v} = \frac{2 \cdot 100 \text{ м}}{27 \text{ м/с}} \approx 7,41 \text{ с}$

6. Вычисляем среднюю мощность:

$P_{ср} = \frac{866200 \text{ Дж}}{7,41 \text{ с}} \approx 116937 \text{ Вт}$

Переведем в киловатты: $116937 \text{ Вт} \approx 117 \text{ кВт}$.

Ответ: средняя мощность, развиваемая двигателем, составляет примерно $117 \text{ кВт}$.

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