Номер 9, страница 23 - гдз по физике 10-11 класс задачник Гельфгат, Генденштейн

Физика, 10-11 класс Задачник, авторы: Гельфгат Илья Маркович, Генденштейн Лев Элевич, Кирик Леонид Анатольевич, издательство Илекса, Москва, 2008, красного цвета

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

Тип: Задачник

Издательство: Илекса

Год издания: 2008 - 2026

Уровень обучения: профильный

Цвет обложки: красный лупа, парень едет на велосипеде

ISBN: 978-5-89237-252-7

Механика. Кинематика. 2. Прямолинейное равноускоренное движение. Олимпиадные задачи - номер 9, страница 23.

App\Models\Task {#1024 // resources/views/models/task/default.blade.php
  #connection: "mysql"
  #table: "tasks"
  #primaryKey: "id"
  #keyType: "int"
  +incrementing: true
  #with: []
  #withCount: []
  +preventsLazyLoading: false
  #perPage: 15
  +exists: true
  +wasRecentlyCreated: false
  #escapeWhenCastingToString: false
  #attributes: array:24 [
    "id" => 1319417
    "created_at" => "2026-04-10 13:58:26"
    "updated_at" => null
    "field_page_start" => "23"
    "field_page_end" => "24"
    "field_url" => "/10-klass/fizika/gelfgat-zadachnik/olimp-9"
    "field_display_title" => "9"
    "field_outside_task" => "0"
    "field_task_type" => Illuminate\Database\Eloquent\Collection {#331
      #items: array:1 [
        0 => App\Models\Term {#1029
          #connection: "mysql"
          #table: "terms"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: false
          #with: []
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          #escapeWhenCastingToString: false
          #attributes: array:6 [
            "id" => 26
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "name" => "номер"
            "field_cases" => array:6 [
              "field_accusative_case" => "номер"
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              "field_genitive_case" => "номера"
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              "field_prepositional_case" => "номере"
            ]
            "field_short_name" => ""
          ]
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            "updated_at" => null
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            "field_cases" => array:6 [
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              "field_nominative_case" => "номер"
              "field_prepositional_case" => "номере"
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            0 => "*"
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    "breadcrumbs" => []
    "edition_groups" => Illuminate\Database\Eloquent\Collection {#1026
      #items: []
      #escapeWhenCastingToString: false
    }
    "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#342
      #items: array:1 [
        0 => App\Models\Branch {#1023
          #connection: "mysql"
          #table: "branches"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
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          #attributes: array:24 [
            "id" => 1319266
            "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 {#333
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              #escapeWhenCastingToString: false
            }
            "field_page_start" => "6"
            "field_branch_display" => "0"
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            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1033
              #items: array:1 [
                0 => App\Models\Book {#1030
                  #connection: "mysql"
                  #table: "books"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
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                  #escapeWhenCastingToString: false
                  #attributes: array:50 [
                    "id" => 5400
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
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                      #items: array:1 [
                        0 => App\Models\Term {#1034
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
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                          #attributes: array:10 [
                            "id" => 6493
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
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                            "field_short_name" => null
                            "field_subject_type" => "technical_subject"
                            "field_translit" => "fizika"
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                          #original: array:10 [
                            "id" => 6493
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
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                              "field_nominative_case" => "физика"
                              "field_prepositional_case" => "физике"
                            ]
                            "field_foreign_lang_name" => null
                            "field_short_name" => null
                            "field_subject_type" => "technical_subject"
                            "field_translit" => "fizika"
                          ]
                          #changes: []
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                          #touches: []
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                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1035
                      #items: array:2 [
                        0 => App\Models\Term {#1036
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 5459
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "10"
                            "field_cases" => array:6 [
                              "field_accusative_case" => "десятый"
                              "field_creative_case" => "десятым"
                              "field_dative_case" => "десятому"
                              "field_genitive_case" => "десятого"
                              "field_nominative_case" => "десятый"
                              "field_prepositional_case" => "десятом"
                            ]
                            "field_translit" => "desjatyj"
                          ]
                          #original: array:6 [
                            "id" => 5459
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "10"
                            "field_cases" => array:6 [
                              "field_accusative_case" => "десятый"
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                              "field_dative_case" => "десятому"
                              "field_genitive_case" => "десятого"
                              "field_nominative_case" => "десятый"
                              "field_prepositional_case" => "десятом"
                            ]
                            "field_translit" => "desjatyj"
                          ]
                          #changes: []
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                          #dateFormat: null
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                          #hidden: []
                          #visible: []
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                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                        1 => App\Models\Term {#1037
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 5460
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "11"
                            "field_cases" => array:6 [
                              "field_accusative_case" => "одиннадцатый"
                              "field_creative_case" => "одиннадцатым"
                              "field_dative_case" => "одиннадцатому"
                              "field_genitive_case" => "одинадцатого"
                              "field_nominative_case" => "одинадцатый"
                              "field_prepositional_case" => "одиннадцатом"
                            ]
                            "field_translit" => "odinadcatyj"
                          ]
                          #original: array:6 [
                            "id" => 5460
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "11"
                            "field_cases" => array:6 [
                              "field_accusative_case" => "одиннадцатый"
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                              "field_genitive_case" => "одинадцатого"
                              "field_nominative_case" => "одинадцатый"
                              "field_prepositional_case" => "одиннадцатом"
                            ]
                            "field_translit" => "odinadcatyj"
                          ]
                          #changes: []
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                          #attributeCastCache: []
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                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1038
                      #items: array:1 [
                        0 => App\Models\Term {#1039
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
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                            "created_at" => "2026-04-10 13:58:26"
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                          #original: array:6 [
                            "id" => 5158
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                    "field_author" => Illuminate\Database\Eloquent\Collection {#1040
                      #items: array:3 [
                        0 => App\Models\Term {#1041
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                          #table: "terms"
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                        1 => App\Models\Term {#1042
                          #connection: "mysql"
                          #table: "terms"
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                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
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                            "field_name" => "Лев"
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                        2 => App\Models\Term {#1043
                          #connection: "mysql"
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                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Кирик"
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                            "field_degree_rp" => null
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                      #items: []
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                      #items: array:1 [
                        0 => App\Models\Term {#1046
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                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Задачник"
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                            ]
                            "field_plural_form" => null
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                            "id" => 6518
                            "created_at" => "2026-04-10 13:58:26"
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                              "field_prepositional_case" => "задачнике"
                            ]
                            "field_plural_form" => null
                            "field_short_name" => null
                            "field_short_name_foreign" => null
                            "field_translit" => "zadachnik"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1047
                      #items: array:1 [
                        0 => App\Models\Term {#1048
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 9
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Россия"
                            "field_cases" => array:6 [
                              "field_accusative_case" => null
                              "field_creative_case" => null
                              "field_dative_case" => null
                              "field_genitive_case" => null
                              "field_nominative_case" => null
                              "field_prepositional_case" => null
                            ]
                            "field_translit" => "rossiya"
                          ]
                          #original: array:6 [
                            "id" => 9
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Россия"
                            "field_cases" => array:6 [
                              "field_accusative_case" => null
                              "field_creative_case" => null
                              "field_dative_case" => null
                              "field_genitive_case" => null
                              "field_nominative_case" => null
                              "field_prepositional_case" => null
                            ]
                            "field_translit" => "rossiya"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1049
                      #items: array:1 [
                        0 => App\Models\Term {#1050
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 15
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Москва"
                            "field_cases" => array:6 [
                              "field_accusative_case" => null
                              "field_creative_case" => null
                              "field_dative_case" => null
                              "field_genitive_case" => null
                              "field_nominative_case" => null
                              "field_prepositional_case" => null
                            ]
                            "field_translit" => "moskva"
                          ]
                          #original: array:6 [
                            "id" => 15
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Москва"
                            "field_cases" => array:6 [
                              "field_accusative_case" => null
                              "field_creative_case" => null
                              "field_dative_case" => null
                              "field_genitive_case" => null
                              "field_nominative_case" => null
                              "field_prepositional_case" => null
                            ]
                            "field_translit" => "moskva"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1051
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1052
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1053
                      #items: array:1 [
                        0 => App\Models\Term {#1054
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 40
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "профильный"
                            "field_cases" => array:6 [
                              "field_accusative_case" => "профильный"
                              "field_creative_case" => "профильным"
                              "field_dative_case" => "профильному"
                              "field_genitive_case" => "профильного"
                              "field_nominative_case" => "профильный"
                              "field_prepositional_case" => "профильном"
                            ]
                            "field_translit" => "profilnyy"
                          ]
                          #original: array:6 [
                            "id" => 40
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "профильный"
                            "field_cases" => array:6 [
                              "field_accusative_case" => "профильный"
                              "field_creative_case" => "профильным"
                              "field_dative_case" => "профильному"
                              "field_genitive_case" => "профильного"
                              "field_nominative_case" => "профильный"
                              "field_prepositional_case" => "профильном"
                            ]
                            "field_translit" => "profilnyy"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1055
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_publication_number" => null
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1056
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1057
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "лупа, парень едет на велосипеде"
                    "field_publication_year" => "2008"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебное издание"
                    "field_allowed" => null
                    "field_reserve_field" => null
                    "field_link_to_source" => null
                    "field_tasks_count" => "459"
                    "field_priority" => null
                    "field_default_folder" => "/fizika_10/gelfgat-z/"
                    "field_isbn" => "978-5-89237-252-7"
                    "field_cover" => array:1 [
                      0 => "/media/fizika_10/gelfgat-z/covers/cover1.webp?ts=1756049816"
                    ]
                    "field_cover_alts" => array:1 [
                      0 => ""
                    ]
                    "field_covers" => array:1 [
                      0 => array:4 [
                        "path" => "/media/fizika_10/gelfgat-z/covers/cover1.webp?ts=1756049816"
                        "alt" => ""
                        "width" => "1566"
                        "height" => "2412"
                      ]
                    ]
                    "field_popular_book" => "0"
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1058
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1059
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1060
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_url" => "/10-klass/fizika/gelfgat-zadachnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1061
                      #items: array:1 [
                        0 => App\Models\Term {#1062
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 46
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "красный"
                            "field_cases" => array:6 [
                              "field_accusative_case" => "красный"
                              "field_creative_case" => "красным"
                              "field_dative_case" => "красному"
                              "field_genitive_case" => "красного"
                              "field_nominative_case" => "красный"
                              "field_prepositional_case" => "красном"
                            ]
                            "field_translit" => "krasnyy"
                          ]
                          #original: array:6 [
                            "id" => 46
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "красный"
                            "field_cases" => array:6 [
                              "field_accusative_case" => "красный"
                              "field_creative_case" => "красным"
                              "field_dative_case" => "красному"
                              "field_genitive_case" => "красного"
                              "field_nominative_case" => "красный"
                              "field_prepositional_case" => "красном"
                            ]
                            "field_translit" => "krasnyy"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [
                      "class" => 381
                      "subject" => 556
                      "class_subject" => 494
                    ]
                  ]
                  #original: array:50 [
                    "id" => 5400
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
                    "field_pages_status" => null
                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1032}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1035}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1038}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1040}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1044}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1045}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1047}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1049}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1051}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1052}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1053}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1055}
                    "field_publication_number" => null
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1056}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1057}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "лупа, парень едет на велосипеде"
                    "field_publication_year" => "2008"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебное издание"
                    "field_allowed" => null
                    "field_reserve_field" => null
                    "field_link_to_source" => null
                    "field_tasks_count" => "459"
                    "field_priority" => null
                    "field_default_folder" => "/fizika_10/gelfgat-z/"
                    "field_isbn" => "978-5-89237-252-7"
                    "field_cover" => array:1 [
                      0 => "/media/fizika_10/gelfgat-z/covers/cover1.webp?ts=1756049816"
                    ]
                    "field_cover_alts" => array:1 [
                      0 => ""
                    ]
                    "field_covers" => array:1 [
                      0 => array:4 [
                        "path" => "/media/fizika_10/gelfgat-z/covers/cover1.webp?ts=1756049816"
                        "alt" => ""
                        "width" => "1566"
                        "height" => "2412"
                      ]
                    ]
                    "field_popular_book" => "0"
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1058}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1059}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1060}
                    "field_url" => "/10-klass/fizika/gelfgat-zadachnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1061}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [
                      "class" => 381
                      "subject" => 556
                      "class_subject" => 494
                    ]
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1063
              #items: []
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 1319266
            "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 {#333}
            "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 {#1033}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1063}
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1064
      #items: array:4 [
        0 => App\Models\Branch {#1023}
        1 => App\Models\Branch {#1065
          #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" => 1319267
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Кинематика"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1066
              #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 {#1067
              #items: array:1 [
                0 => App\Models\Book {#1030}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1068
              #items: array:1 [
                0 => App\Models\Branch {#1069
                  #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" => 1319266
                    "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 {#1070
                      #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 {#1071
                      #items: array:1 [
                        0 => App\Models\Book {#1030}
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1072
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                  ]
                  #original: array:24 [
                    "id" => 1319266
                    "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 {#1070}
                    "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 {#1071}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1072}
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 1319267
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Кинематика"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1066}
            "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 {#1067}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1068}
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        2 => App\Models\Branch {#1073
          #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" => 1319271
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "2. Прямолинейное равноускоренное движение"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1074
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "16"
            "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 {#1075
              #items: array:1 [
                0 => App\Models\Book {#1030}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1076
              #items: array:1 [
                0 => App\Models\Branch {#1077
                  #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" => 1319267
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_display_title" => "Кинематика"
                    "field_branch_order" => null
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1078
                      #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 {#1079
                      #items: array:1 [
                        0 => App\Models\Book {#1030}
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1080
                      #items: array:1 [
                        0 => App\Models\Branch {#1081
                          #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 [ …24]
                          #original: array:24 [ …24]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                           …8
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                  ]
                  #original: array:24 [
                    "id" => 1319267
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_display_title" => "Кинематика"
                    "field_branch_order" => null
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1078}
                    "field_page_start" => "6"
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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 {#1079}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1080}
                  ]
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                  #attributeCastCache: []
                  #dateFormat: null
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                  #dispatchesEvents: []
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                  #relations: []
                  #touches: []
                  +timestamps: true
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                  #hidden: []
                  #visible: []
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                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
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            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "2. Прямолинейное равноускоренное движение"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1074}
            "field_page_start" => "16"
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            "book" => Illuminate\Database\Eloquent\Collection {#1075}
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          ]
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          #dateFormat: null
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          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        3 => App\Models\Branch {#1116
          #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" => 1319273
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Олимпиадные задачи"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1117
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "21"
            "field_branch_display" => "0"
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            "field_display_branch_in_title" => "1"
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            "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 {#1118
              #items: array:1 [
                0 => App\Models\Book {#1030}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1119
              #items: array:1 [
                0 => App\Models\Branch {#1120
                  #connection: "mysql"
                  #table: "branches"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [
                    "id" => 1319271
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_display_title" => "2. Прямолинейное равноускоренное движение"
                    "field_branch_order" => null
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1121
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_page_start" => "16"
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                    "field_navigation_title" => null
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                    "field_branch_cover" => []
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                    "book" => Illuminate\Database\Eloquent\Collection {#1122
                      #items: array:1 [
                        0 => App\Models\Book {#1030}
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1123
                      #items: array:1 [
                        0 => App\Models\Branch {#1124 …30}
                      ]
                      #escapeWhenCastingToString: false
                    }
                  ]
                  #original: array:24 [
                    "id" => 1319271
                    "created_at" => "2026-04-10 13:58:26"
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                    "field_display_title" => "2. Прямолинейное равноускоренное движение"
                    "field_branch_order" => null
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1121}
                    "field_page_start" => "16"
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                    "book" => Illuminate\Database\Eloquent\Collection {#1122}
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            "field_navigation_title" => null
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            "field_h1" => null
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            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1119}
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      ]
      #escapeWhenCastingToString: false
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    "content" => Illuminate\Database\Eloquent\Collection {#1163
      #items: array:2 [
        0 => App\Models\Element {#1164
          #connection: "mysql"
          #table: "elements"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
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          +exists: true
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          #escapeWhenCastingToString: false
          #attributes: array:7 [
            "id" => 1493987
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1165
              #items: array:1 [
                0 => App\Models\Edition {#1166
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:21 [
                    "id" => 5430
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Условие"
                    "field_order" => "1"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1167
                      #items: array:1 [
                        0 => App\Models\Term {#1168 …30}
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_content_type" => "free"
                    "field_content_mode" => "text, image"
                    "field_page_content_mode" => "image"
                    "field_content_text_checked" => null
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Автор"
                    "field_moderator" => "stas"
                    "field_edition_type" => "statement"
                    "field_root_dir" => "0-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1169
                      #items: []
                      #escapeWhenCastingToString: false
                    }
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                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1170
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_process_formula" => "katex"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1171
                      #items: []
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                    "field_content_source" => null
                  ]
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                    "title" => "Условие"
                    "field_order" => "1"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1167}
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            "task" => array:2 [
              "refs" => "1319417"
              "type" => "task"
            ]
            "text" => "<p><strong>О-9.</strong> В момент, когда опоздавший пассажир вбежал на платформу, с ним поравнялось начало предпоследнего вагона, который прошел мимо него за время $t_1$. Последний вагон прошел мимо пассажира за время $t_2$. На сколько опоздал пассажир к отходу поезда? Поезд движется равноускоренно. Длина вагонов одинакова.</p><p>$\tau = \frac{t_2^2 + 2t_1t_2 - t_1^2}{2(t_1 - t_2)}$</p><p><strong><em>Решение.</em></strong> Обозначим: $L_1$ — длина поезда без двух последних вагонов; $L_2$ — длина поезда без последнего вагона; $\text{L}$ — длина всего поезда; $\text{l}$ — длина одного вагона; $\tau$ — время, на которое опоздал пассажир.</p><p>Тогда длину одного вагона мы можем выразить следующим образом: $l = L_2 - L_1$ и $l = L - L_2$. Из уравнения для равноускоренного движения запишем: $L_1 = \frac{a\tau^2}{2}$, $L_2 = \frac{a(\tau+t_1)^2}{2}$ и $L = \frac{a(\tau+t_1+t_2)^2}{2}$.</p><p>Исключая длину вагона $\text{l}$ из этих уравнений, получим: $l = \frac{a(\tau+t_1)^2}{2} - \frac{a\tau^2}{2} = \frac{a(\tau+t_1+t_2)^2}{2} - \frac{a(\tau+t_1)^2}{2}$, или $2(\tau+t_1)^2 = \tau^2 + (\tau+t_1+t_2)^2$. $2(\tau+t_1)^2 = \tau^2 + [(\tau+t_1)+t_2]^2$, откуда получаем: $= \tau^2 + (\tau+t_1)^2 + 2t_2(\tau+t_1) + t_2^2$. $\tau^2 + 2\tau t_1 + t_1^2 = \tau^2 + 2\tau t_2 + 2t_1t_2 + t_2^2$, далее $2\tau(t_1 - t_2) = t_2^2 + 2t_1t_2 - t_1^2$.</p><p>Окончательно получаем: $\tau = \frac{t_2^2 + 2t_1t_2 - t_1^2}{2(t_1 - t_2)}$.</p>"
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          ]
          #original: array:7 [
            "id" => 1493987
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1165}
            "task" => array:2 [
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            "text" => "<p><strong>О-9.</strong> В момент, когда опоздавший пассажир вбежал на платформу, с ним поравнялось начало предпоследнего вагона, который прошел мимо него за время $t_1$. Последний вагон прошел мимо пассажира за время $t_2$. На сколько опоздал пассажир к отходу поезда? Поезд движется равноускоренно. Длина вагонов одинакова.</p><p>$\tau = \frac{t_2^2 + 2t_1t_2 - t_1^2}{2(t_1 - t_2)}$</p><p><strong><em>Решение.</em></strong> Обозначим: $L_1$ — длина поезда без двух последних вагонов; $L_2$ — длина поезда без последнего вагона; $\text{L}$ — длина всего поезда; $\text{l}$ — длина одного вагона; $\tau$ — время, на которое опоздал пассажир.</p><p>Тогда длину одного вагона мы можем выразить следующим образом: $l = L_2 - L_1$ и $l = L - L_2$. Из уравнения для равноускоренного движения запишем: $L_1 = \frac{a\tau^2}{2}$, $L_2 = \frac{a(\tau+t_1)^2}{2}$ и $L = \frac{a(\tau+t_1+t_2)^2}{2}$.</p><p>Исключая длину вагона $\text{l}$ из этих уравнений, получим: $l = \frac{a(\tau+t_1)^2}{2} - \frac{a\tau^2}{2} = \frac{a(\tau+t_1+t_2)^2}{2} - \frac{a(\tau+t_1)^2}{2}$, или $2(\tau+t_1)^2 = \tau^2 + (\tau+t_1+t_2)^2$. $2(\tau+t_1)^2 = \tau^2 + [(\tau+t_1)+t_2]^2$, откуда получаем: $= \tau^2 + (\tau+t_1)^2 + 2t_2(\tau+t_1) + t_2^2$. $\tau^2 + 2\tau t_1 + t_1^2 = \tau^2 + 2\tau t_2 + 2t_1t_2 + t_2^2$, далее $2\tau(t_1 - t_2) = t_2^2 + 2t_1t_2 - t_1^2$.</p><p>Окончательно получаем: $\tau = \frac{t_2^2 + 2t_1t_2 - t_1^2}{2(t_1 - t_2)}$.</p>"
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            "text" => "<p><strong>Дано:</strong></p><p>$t_1$ – время прохождения предпоследнего вагона</p><p>$t_2$ – время прохождения последнего вагона</p><p>Движение поезда равноускоренное, начальная скорость $v_0 = 0$. Длины всех вагонов одинаковы.</p><p><strong>Найти:</strong></p><p>$\tau$ – время, на которое опоздал пассажир.</p><p><strong>Решение:</strong></p><p>Пусть поезд начинает движение в момент времени $t=0$ с ускорением $a$. Пассажир приходит на платформу в момент времени $\tau$, когда поезд уже движется. Это и есть время его опоздания. Будем считать, что пассажир стоит в точке с координатой $x=0$.</p><p>Путь, пройденный телом при равноускоренном движении из состояния покоя, определяется формулой $S = \frac{at^2}{2}$.</p><p>В момент времени $\tau$, когда пассажир вбежал на платформу, с ним поравнялось начало предпоследнего вагона. Это означает, что к этому моменту некоторая часть поезда уже прошла мимо него. Обозначим эту часть как $S_1$.</p><p>Таким образом, путь, пройденный головой поезда за время $\tau$, равен $S_1 = \frac{a\tau^2}{2}$.</p><p>Предпоследний вагон прошел мимо пассажира за время $t_1$. Это значит, что конец предпоследнего вагона (и начало последнего) оказался на уровне пассажира в момент времени $\tau + t_1$. Путь, пройденный головой поезда к этому моменту, обозначим $S_2$.</p><p>$S_2 = \frac{a(\tau + t_1)^2}{2}$</p><p>Последний вагон прошел мимо пассажира за время $t_2$. Это значит, что хвост поезда поравнялся с пассажиром в момент времени $\tau + t_1 + t_2$. Полный путь, пройденный головой поезда, равен длине всего поезда $S$.</p><p>$S = \frac{a(\tau + t_1 + t_2)^2}{2}$</p><p>По условию, длина всех вагонов одинакова. Обозначим длину одного вагона как $l$.</p><p>Длину предпоследнего вагона можно выразить как разность путей $S_2$ и $S_1$:</p><p>$l = S_2 - S_1 = \frac{a(\tau + t_1)^2}{2} - \frac{a\tau^2}{2}$</p><p>Длину последнего вагона можно выразить как разность путей $S$ и $S_2$:</p><p>$l = S - S_2 = \frac{a(\tau + t_1 + t_2)^2}{2} - \frac{a(\tau + t_1)^2}{2}$</p><p>Приравняем два выражения для длины вагона $l$:</p><p>$\frac{a(\tau + t_1)^2}{2} - \frac{a\tau^2}{2} = \frac{a(\tau + t_1 + t_2)^2}{2} - \frac{a(\tau + t_1)^2}{2}$</p><p>Сократим обе части уравнения на $\frac{a}{2}$ (так как ускорение $a \neq 0$):</p><p>$(\tau + t_1)^2 - \tau^2 = (\tau + t_1 + t_2)^2 - (\tau + t_1)^2$</p><p>Перенесем $(\tau + t_1)^2$ из правой части в левую:</p><p>$2(\tau + t_1)^2 = \tau^2 + (\tau + t_1 + t_2)^2$</p><p>Теперь раскроем скобки и решим уравнение относительно $\tau$.</p><p>$2(\tau^2 + 2\tau t_1 + t_1^2) = \tau^2 + ((\tau + t_1) + t_2)^2$</p><p>$2\tau^2 + 4\tau t_1 + 2t_1^2 = \tau^2 + (\tau + t_1)^2 + 2t_2(\tau + t_1) + t_2^2$</p><p>$2\tau^2 + 4\tau t_1 + 2t_1^2 = \tau^2 + (\tau^2 + 2\tau t_1 + t_1^2) + 2\tau t_2 + 2t_1t_2 + t_2^2$</p><p>$2\tau^2 + 4\tau t_1 + 2t_1^2 = 2\tau^2 + 2\tau t_1 + t_1^2 + 2\tau t_2 + 2t_1t_2 + t_2^2$</p><p>Сократим $2\tau^2$ в обеих частях:</p><p>$4\tau t_1 + 2t_1^2 = 2\tau t_1 + 2\tau t_2 + 2t_1t_2 + t_1^2 + t_2^2$</p><p>Сгруппируем члены, содержащие $\tau$, в левой части, а остальные — в правой:</p><p>$4\tau t_1 - 2\tau t_1 - 2\tau t_2 = 2t_1t_2 + t_1^2 + t_2^2 - 2t_1^2$</p><p>Упростим выражение:</p><p>$2\tau t_1 - 2\tau t_2 = t_2^2 + 2t_1t_2 - t_1^2$</p><p>Вынесем $2\tau$ за скобки:</p><p>$2\tau(t_1 - t_2) = t_2^2 + 2t_1t_2 - t_1^2$</p><p>Наконец, выразим $\tau$:</p><p>$\tau = \frac{t_2^2 + 2t_1t_2 - t_1^2}{2(t_1 - t_2)}$</p><p>Поскольку поезд движется с ускорением, каждый следующий вагон проходит мимо наблюдателя быстрее предыдущего, поэтому $t_1 &gt; t_2$, и знаменатель в формуле положителен.</p><p><strong>Ответ:</strong> $\tau = \frac{t_2^2 + 2t_1t_2 - t_1^2}{2(t_1 - t_2)}$</p>"
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            "created_at" => "2026-04-10 13:58:26"
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            "edition" => Illuminate\Database\Eloquent\Collection {#1173}
            "task" => array:2 [
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              "type" => "task"
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            "text" => "<p><strong>Дано:</strong></p><p>$t_1$ – время прохождения предпоследнего вагона</p><p>$t_2$ – время прохождения последнего вагона</p><p>Движение поезда равноускоренное, начальная скорость $v_0 = 0$. Длины всех вагонов одинаковы.</p><p><strong>Найти:</strong></p><p>$\tau$ – время, на которое опоздал пассажир.</p><p><strong>Решение:</strong></p><p>Пусть поезд начинает движение в момент времени $t=0$ с ускорением $a$. Пассажир приходит на платформу в момент времени $\tau$, когда поезд уже движется. Это и есть время его опоздания. Будем считать, что пассажир стоит в точке с координатой $x=0$.</p><p>Путь, пройденный телом при равноускоренном движении из состояния покоя, определяется формулой $S = \frac{at^2}{2}$.</p><p>В момент времени $\tau$, когда пассажир вбежал на платформу, с ним поравнялось начало предпоследнего вагона. Это означает, что к этому моменту некоторая часть поезда уже прошла мимо него. Обозначим эту часть как $S_1$.</p><p>Таким образом, путь, пройденный головой поезда за время $\tau$, равен $S_1 = \frac{a\tau^2}{2}$.</p><p>Предпоследний вагон прошел мимо пассажира за время $t_1$. Это значит, что конец предпоследнего вагона (и начало последнего) оказался на уровне пассажира в момент времени $\tau + t_1$. Путь, пройденный головой поезда к этому моменту, обозначим $S_2$.</p><p>$S_2 = \frac{a(\tau + t_1)^2}{2}$</p><p>Последний вагон прошел мимо пассажира за время $t_2$. Это значит, что хвост поезда поравнялся с пассажиром в момент времени $\tau + t_1 + t_2$. Полный путь, пройденный головой поезда, равен длине всего поезда $S$.</p><p>$S = \frac{a(\tau + t_1 + t_2)^2}{2}$</p><p>По условию, длина всех вагонов одинакова. Обозначим длину одного вагона как $l$.</p><p>Длину предпоследнего вагона можно выразить как разность путей $S_2$ и $S_1$:</p><p>$l = S_2 - S_1 = \frac{a(\tau + t_1)^2}{2} - \frac{a\tau^2}{2}$</p><p>Длину последнего вагона можно выразить как разность путей $S$ и $S_2$:</p><p>$l = S - S_2 = \frac{a(\tau + t_1 + t_2)^2}{2} - \frac{a(\tau + t_1)^2}{2}$</p><p>Приравняем два выражения для длины вагона $l$:</p><p>$\frac{a(\tau + t_1)^2}{2} - \frac{a\tau^2}{2} = \frac{a(\tau + t_1 + t_2)^2}{2} - \frac{a(\tau + t_1)^2}{2}$</p><p>Сократим обе части уравнения на $\frac{a}{2}$ (так как ускорение $a \neq 0$):</p><p>$(\tau + t_1)^2 - \tau^2 = (\tau + t_1 + t_2)^2 - (\tau + t_1)^2$</p><p>Перенесем $(\tau + t_1)^2$ из правой части в левую:</p><p>$2(\tau + t_1)^2 = \tau^2 + (\tau + t_1 + t_2)^2$</p><p>Теперь раскроем скобки и решим уравнение относительно $\tau$.</p><p>$2(\tau^2 + 2\tau t_1 + t_1^2) = \tau^2 + ((\tau + t_1) + t_2)^2$</p><p>$2\tau^2 + 4\tau t_1 + 2t_1^2 = \tau^2 + (\tau + t_1)^2 + 2t_2(\tau + t_1) + t_2^2$</p><p>$2\tau^2 + 4\tau t_1 + 2t_1^2 = \tau^2 + (\tau^2 + 2\tau t_1 + t_1^2) + 2\tau t_2 + 2t_1t_2 + t_2^2$</p><p>$2\tau^2 + 4\tau t_1 + 2t_1^2 = 2\tau^2 + 2\tau t_1 + t_1^2 + 2\tau t_2 + 2t_1t_2 + t_2^2$</p><p>Сократим $2\tau^2$ в обеих частях:</p><p>$4\tau t_1 + 2t_1^2 = 2\tau t_1 + 2\tau t_2 + 2t_1t_2 + t_1^2 + t_2^2$</p><p>Сгруппируем члены, содержащие $\tau$, в левой части, а остальные — в правой:</p><p>$4\tau t_1 - 2\tau t_1 - 2\tau t_2 = 2t_1t_2 + t_1^2 + t_2^2 - 2t_1^2$</p><p>Упростим выражение:</p><p>$2\tau t_1 - 2\tau t_2 = t_2^2 + 2t_1t_2 - t_1^2$</p><p>Вынесем $2\tau$ за скобки:</p><p>$2\tau(t_1 - t_2) = t_2^2 + 2t_1t_2 - t_1^2$</p><p>Наконец, выразим $\tau$:</p><p>$\tau = \frac{t_2^2 + 2t_1t_2 - t_1^2}{2(t_1 - t_2)}$</p><p>Поскольку поезд движется с ускорением, каждый следующий вагон проходит мимо наблюдателя быстрее предыдущего, поэтому $t_1 &gt; t_2$, и знаменатель в формуле положителен.</p><p><strong>Ответ:</strong> $\tau = \frac{t_2^2 + 2t_1t_2 - t_1^2}{2(t_1 - t_2)}$</p>"
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    "book" => Illuminate\Database\Eloquent\Collection {#1180
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                    "created_at" => "2026-04-10 13:58:26"
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                    "field_country" => Illuminate\Database\Eloquent\Collection {#1212
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}
№9 (с. 23)
Условие. №9 (с. 23)
скриншот условия
Физика, 10-11 класс Задачник, авторы: Гельфгат Илья Маркович, Генденштейн Лев Элевич, Кирик Леонид Анатольевич, издательство Илекса, Москва, 2008, красного цвета, страница 23, номер 9, Условие
Физика, 10-11 класс Задачник, авторы: Гельфгат Илья Маркович, Генденштейн Лев Элевич, Кирик Леонид Анатольевич, издательство Илекса, Москва, 2008, красного цвета, страница 23, номер 9, Условие (продолжение 2)

О-9. В момент, когда опоздавший пассажир вбежал на платформу, с ним поравнялось начало предпоследнего вагона, который прошел мимо него за время $t_1$. Последний вагон прошел мимо пассажира за время $t_2$. На сколько опоздал пассажир к отходу поезда? Поезд движется равноускоренно. Длина вагонов одинакова.

$\tau = \frac{t_2^2 + 2t_1t_2 - t_1^2}{2(t_1 - t_2)}$

Решение. Обозначим: $L_1$ — длина поезда без двух последних вагонов; $L_2$ — длина поезда без последнего вагона; $\text{L}$ — длина всего поезда; $\text{l}$ — длина одного вагона; $\tau$ — время, на которое опоздал пассажир.

Тогда длину одного вагона мы можем выразить следующим образом: $l = L_2 - L_1$ и $l = L - L_2$. Из уравнения для равноускоренного движения запишем: $L_1 = \frac{a\tau^2}{2}$, $L_2 = \frac{a(\tau+t_1)^2}{2}$ и $L = \frac{a(\tau+t_1+t_2)^2}{2}$.

Исключая длину вагона $\text{l}$ из этих уравнений, получим: $l = \frac{a(\tau+t_1)^2}{2} - \frac{a\tau^2}{2} = \frac{a(\tau+t_1+t_2)^2}{2} - \frac{a(\tau+t_1)^2}{2}$, или $2(\tau+t_1)^2 = \tau^2 + (\tau+t_1+t_2)^2$. $2(\tau+t_1)^2 = \tau^2 + [(\tau+t_1)+t_2]^2$, откуда получаем: $= \tau^2 + (\tau+t_1)^2 + 2t_2(\tau+t_1) + t_2^2$. $\tau^2 + 2\tau t_1 + t_1^2 = \tau^2 + 2\tau t_2 + 2t_1t_2 + t_2^2$, далее $2\tau(t_1 - t_2) = t_2^2 + 2t_1t_2 - t_1^2$.

Окончательно получаем: $\tau = \frac{t_2^2 + 2t_1t_2 - t_1^2}{2(t_1 - t_2)}$.

Решение. №9 (с. 23)

Дано:

$t_1$ – время прохождения предпоследнего вагона

$t_2$ – время прохождения последнего вагона

Движение поезда равноускоренное, начальная скорость $v_0 = 0$. Длины всех вагонов одинаковы.

Найти:

$\tau$ – время, на которое опоздал пассажир.

Решение:

Пусть поезд начинает движение в момент времени $t=0$ с ускорением $a$. Пассажир приходит на платформу в момент времени $\tau$, когда поезд уже движется. Это и есть время его опоздания. Будем считать, что пассажир стоит в точке с координатой $x=0$.

Путь, пройденный телом при равноускоренном движении из состояния покоя, определяется формулой $S = \frac{at^2}{2}$.

В момент времени $\tau$, когда пассажир вбежал на платформу, с ним поравнялось начало предпоследнего вагона. Это означает, что к этому моменту некоторая часть поезда уже прошла мимо него. Обозначим эту часть как $S_1$.

Таким образом, путь, пройденный головой поезда за время $\tau$, равен $S_1 = \frac{a\tau^2}{2}$.

Предпоследний вагон прошел мимо пассажира за время $t_1$. Это значит, что конец предпоследнего вагона (и начало последнего) оказался на уровне пассажира в момент времени $\tau + t_1$. Путь, пройденный головой поезда к этому моменту, обозначим $S_2$.

$S_2 = \frac{a(\tau + t_1)^2}{2}$

Последний вагон прошел мимо пассажира за время $t_2$. Это значит, что хвост поезда поравнялся с пассажиром в момент времени $\tau + t_1 + t_2$. Полный путь, пройденный головой поезда, равен длине всего поезда $S$.

$S = \frac{a(\tau + t_1 + t_2)^2}{2}$

По условию, длина всех вагонов одинакова. Обозначим длину одного вагона как $l$.

Длину предпоследнего вагона можно выразить как разность путей $S_2$ и $S_1$:

$l = S_2 - S_1 = \frac{a(\tau + t_1)^2}{2} - \frac{a\tau^2}{2}$

Длину последнего вагона можно выразить как разность путей $S$ и $S_2$:

$l = S - S_2 = \frac{a(\tau + t_1 + t_2)^2}{2} - \frac{a(\tau + t_1)^2}{2}$

Приравняем два выражения для длины вагона $l$:

$\frac{a(\tau + t_1)^2}{2} - \frac{a\tau^2}{2} = \frac{a(\tau + t_1 + t_2)^2}{2} - \frac{a(\tau + t_1)^2}{2}$

Сократим обе части уравнения на $\frac{a}{2}$ (так как ускорение $a \neq 0$):

$(\tau + t_1)^2 - \tau^2 = (\tau + t_1 + t_2)^2 - (\tau + t_1)^2$

Перенесем $(\tau + t_1)^2$ из правой части в левую:

$2(\tau + t_1)^2 = \tau^2 + (\tau + t_1 + t_2)^2$

Теперь раскроем скобки и решим уравнение относительно $\tau$.

$2(\tau^2 + 2\tau t_1 + t_1^2) = \tau^2 + ((\tau + t_1) + t_2)^2$

$2\tau^2 + 4\tau t_1 + 2t_1^2 = \tau^2 + (\tau + t_1)^2 + 2t_2(\tau + t_1) + t_2^2$

$2\tau^2 + 4\tau t_1 + 2t_1^2 = \tau^2 + (\tau^2 + 2\tau t_1 + t_1^2) + 2\tau t_2 + 2t_1t_2 + t_2^2$

$2\tau^2 + 4\tau t_1 + 2t_1^2 = 2\tau^2 + 2\tau t_1 + t_1^2 + 2\tau t_2 + 2t_1t_2 + t_2^2$

Сократим $2\tau^2$ в обеих частях:

$4\tau t_1 + 2t_1^2 = 2\tau t_1 + 2\tau t_2 + 2t_1t_2 + t_1^2 + t_2^2$

Сгруппируем члены, содержащие $\tau$, в левой части, а остальные — в правой:

$4\tau t_1 - 2\tau t_1 - 2\tau t_2 = 2t_1t_2 + t_1^2 + t_2^2 - 2t_1^2$

Упростим выражение:

$2\tau t_1 - 2\tau t_2 = t_2^2 + 2t_1t_2 - t_1^2$

Вынесем $2\tau$ за скобки:

$2\tau(t_1 - t_2) = t_2^2 + 2t_1t_2 - t_1^2$

Наконец, выразим $\tau$:

$\tau = \frac{t_2^2 + 2t_1t_2 - t_1^2}{2(t_1 - t_2)}$

Поскольку поезд движется с ускорением, каждый следующий вагон проходит мимо наблюдателя быстрее предыдущего, поэтому $t_1 > t_2$, и знаменатель в формуле положителен.

Ответ: $\tau = \frac{t_2^2 + 2t_1t_2 - t_1^2}{2(t_1 - t_2)}$

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