Номер 19, страница 104, часть 1 - гдз по физике 9 класс учебник Генденштейн, Булатова

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

Тип: Учебник

Издательство: Бином

Год издания: 2016 - 2026

Часть: 1

Цвет обложки: бирюзовый

ISBN: 978-5-9963-3062-1

Часть 1. Механические явления. Глава II. Динамика. Параграф 11. Силы трения - номер 19, страница 104.

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                    "field_link_to_source" => null
                    "field_tasks_count" => "1111"
                    "field_priority" => null
                    "field_default_folder" => "/fizika_09/gendenshtejn-u/"
                    "field_isbn" => "978-5-9963-3062-1"
                    "field_cover" => array:2 [ …2]
                    "field_cover_alts" => array:2 [ …2]
                    "field_covers" => array:2 [ …2]
                    "field_popular_book" => "0"
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1104 …2}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1105 …2}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1106 …2}
                    "field_url" => "/9-klass/fizika/gendenshtejn-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1107 …2}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [ …3]
                  ]
                  #changes: []
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                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
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                  #touches: []
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                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1109
              #items: []
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 1433206
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => null
            "field_branch_order" => "1"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1076}
            "field_page_start" => "6"
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            "field_display_branch_in_title" => "1"
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            "field_h1" => null
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            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1077}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1109}
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          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        1 => App\Models\Branch {#1110
          #connection: "mysql"
          #table: "branches"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:24 [
            "id" => 1433207
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Механические явления"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1111
              #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
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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 {#1112
              #items: array:1 [
                0 => App\Models\Book {#1113
                  #connection: "mysql"
                  #table: "books"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:50 [
                    "id" => 2980
                    "created_at" => "2026-04-10 13:58:26"
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                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1114 …2}
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                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1118 …2}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1120 …2}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1125 …2}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1126 …2}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1128 …2}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1130 …2}
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                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1134 …2}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1135 …2}
                    "field_publication_number" => null
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1136 …2}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1137 …2}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => null
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                    "field_part" => "1, 2"
                    "field_part_writing" => "Часть"
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                    "field_for_whom" => "Учебное издание"
                    "field_allowed" => null
                    "field_reserve_field" => null
                    "field_link_to_source" => null
                    "field_tasks_count" => "1111"
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                    "field_default_folder" => "/fizika_09/gendenshtejn-u/"
                    "field_isbn" => "978-5-9963-3062-1"
                    "field_cover" => array:2 [ …2]
                    "field_cover_alts" => array:2 [ …2]
                    "field_covers" => array:2 [ …2]
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                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1141 …2}
                    "field_url" => "/9-klass/fizika/gendenshtejn-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1142 …2}
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                    "breadcrumbs" => array:3 [ …3]
                  ]
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                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1114 …2}
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                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1125 …2}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1126 …2}
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                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1135 …2}
                    "field_publication_number" => null
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1136 …2}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1137 …2}
                    "field_under_the_edition_degree" => null
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                    "field_default_folder" => "/fizika_09/gendenshtejn-u/"
                    "field_isbn" => "978-5-9963-3062-1"
                    "field_cover" => array:2 [ …2]
                    "field_cover_alts" => array:2 [ …2]
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                    "breadcrumbs" => array:3 [ …3]
                  ]
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                    0 => "*"
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                }
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1144
              #items: array:1 [
                0 => App\Models\Branch {#1145
                  #connection: "mysql"
                  #table: "branches"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
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                  #perPage: 15
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                  #escapeWhenCastingToString: false
                  #attributes: array:24 [
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                    "created_at" => "2026-04-10 13:58:26"
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                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1146 …2}
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                    "book" => Illuminate\Database\Eloquent\Collection {#1148 …2}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1180 …2}
                  ]
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                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1146 …2}
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                    "book" => Illuminate\Database\Eloquent\Collection {#1148 …2}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1180 …2}
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                  #changes: []
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                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
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                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 1433207
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Механические явления"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1111}
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            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1112}
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          #hidden: []
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          #guarded: array:1 [
            0 => "*"
          ]
        }
        2 => App\Models\Branch {#1181
          #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" => 1433214
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Динамика"
            "field_branch_order" => "II"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1182
              #items: array:1 [
                0 => App\Models\Term {#1183
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:7 [
                    "id" => 29
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Глава"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => null
                  ]
                  #original: array:7 [
                    "id" => 29
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Глава"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => null
                  ]
                  #changes: []
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                  #attributeCastCache: []
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                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "59"
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            "field_navigation_title" => null
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            "field_metatags_description" => null
            "field_h1" => null
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            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1184
              #items: array:1 [
                0 => App\Models\Book {#1185
                  #connection: "mysql"
                  #table: "books"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:50 [
                    "id" => 2980
                    "created_at" => "2026-04-10 13:58:26"
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                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1186 …2}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1188 …2}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1190 …2}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1192 …2}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1197 …2}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1198 …2}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1200 …2}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1202 …2}
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                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1206 …2}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1207 …2}
                    "field_publication_number" => null
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1208 …2}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1209 …2}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => null
                    "field_publication_year" => "2016"
                    "field_publication_year_until" => null
                    "field_part" => "1, 2"
                    "field_part_writing" => "Часть"
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебное издание"
                    "field_allowed" => null
                    "field_reserve_field" => null
                    "field_link_to_source" => null
                    "field_tasks_count" => "1111"
                    "field_priority" => null
                    "field_default_folder" => "/fizika_09/gendenshtejn-u/"
                    "field_isbn" => "978-5-9963-3062-1"
                    "field_cover" => array:2 [ …2]
                    "field_cover_alts" => array:2 [ …2]
                    "field_covers" => array:2 [ …2]
                    "field_popular_book" => "0"
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1211 …2}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1212 …2}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1213 …2}
                    "field_url" => "/9-klass/fizika/gendenshtejn-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1214 …2}
                    "field_metatags_title" => null
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                    "breadcrumbs" => array:3 [ …3]
                  ]
                  #original: array:50 [
                    "id" => 2980
                    "created_at" => "2026-04-10 13:58:26"
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                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1186 …2}
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                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1190 …2}
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                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1197 …2}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1198 …2}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1200 …2}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1202 …2}
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                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1206 …2}
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                    "field_publication_number" => null
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1208 …2}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1209 …2}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => null
                    "field_publication_year" => "2016"
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                    "field_part" => "1, 2"
                    "field_part_writing" => "Часть"
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебное издание"
                    "field_allowed" => null
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                    "field_default_folder" => "/fizika_09/gendenshtejn-u/"
                    "field_isbn" => "978-5-9963-3062-1"
                    "field_cover" => array:2 [ …2]
                    "field_cover_alts" => array:2 [ …2]
                    "field_covers" => array:2 [ …2]
                    "field_popular_book" => "0"
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1211 …2}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1212 …2}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1213 …2}
                    "field_url" => "/9-klass/fizika/gendenshtejn-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1214 …2}
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                    "breadcrumbs" => array:3 [ …3]
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                    0 => "*"
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            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1216
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                  #attributes: array:24 [
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                    "created_at" => "2026-04-10 13:58:26"
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                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1218 …2}
                    "field_page_start" => "6"
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                    "field_branch_cover" => []
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                    "book" => Illuminate\Database\Eloquent\Collection {#1219 …2}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1220 …2}
                  ]
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                    "id" => 1433207
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                    "updated_at" => null
                    "field_display_title" => "Механические явления"
                    "field_branch_order" => null
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1218 …2}
                    "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"
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                    "field_navigation_title" => null
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                    "field_branch_cover" => []
                    "field_branch_covers" => []
                    "book" => Illuminate\Database\Eloquent\Collection {#1219 …2}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1220 …2}
                  ]
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          #original: array:24 [
            "id" => 1433214
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Динамика"
            "field_branch_order" => "II"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1182}
            "field_page_start" => "59"
            "field_branch_display" => "0"
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            "field_display_branch_in_title" => "1"
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            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1184}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1216}
          ]
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            0 => "*"
          ]
        }
        3 => App\Models\Branch {#1226
          #connection: "mysql"
          #table: "branches"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
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          #perPage: 15
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          #escapeWhenCastingToString: false
          #attributes: array:24 [
            "id" => 1433220
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Силы трения"
            "field_branch_order" => "11"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1227
              #items: array:1 [
                0 => App\Models\Term {#1228
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:7 [
                    "id" => 32
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Параграф"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => "§"
                  ]
                  #original: array:7 [
                    "id" => 32
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Параграф"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => "§"
                  ]
                  #changes: []
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                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
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                  #touches: []
                  +timestamps: true
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                  #hidden: []
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                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "96"
            "field_branch_display" => "0"
            "field_branch_expanded" => "0"
            "field_display_branch_in_title" => "1"
            "field_display_task_interval" => "0"
            "field_display_branch_page" => "1"
            "field_branch_title_in_content" => "0"
            "field_navigation_title" => null
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1229
              #items: array:1 [
                0 => App\Models\Book {#1230
                  #connection: "mysql"
                  #table: "books"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:50 [
                    "id" => 2980
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
                    "field_pages_status" => null
                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1231 …2}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1233 …2}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1235 …2}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1237 …2}
                     …41
                  ]
                  #original: array:50 [ …50]
                  #changes: []
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                  #dateFormat: null
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                  +timestamps: true
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                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1261
              #items: array:1 [
                0 => App\Models\Branch {#1262
                  #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: []
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                  #attributeCastCache: []
                  #dateFormat: null
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                  +timestamps: true
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                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
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          ]
          #original: array:24 [
            "id" => 1433220
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Силы трения"
            "field_branch_order" => "11"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1227}
            "field_page_start" => "96"
            "field_branch_display" => "0"
            "field_branch_expanded" => "0"
            "field_display_branch_in_title" => "1"
            "field_display_task_interval" => "0"
            "field_display_branch_page" => "1"
            "field_branch_title_in_content" => "0"
            "field_navigation_title" => null
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1229}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1261}
          ]
          #changes: []
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      ]
      #escapeWhenCastingToString: false
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    "content" => Illuminate\Database\Eloquent\Collection {#1308
      #items: array:2 [
        0 => App\Models\Element {#1318
          #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" => 1696375
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1327
              #items: array:1 [
                0 => App\Models\Edition {#1319
                  #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 [ …21]
                  #original: array:21 [ …21]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
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                  #touches: []
                  +timestamps: true
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                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "1433634"
              "type" => "task"
            ]
            "text" => "<p><strong>19.</strong> Деревянный брусок движется с постоянной скоростью по столу под действием некоторой горизонтально направленной силы. С каким ускорением будет двигаться этот брусок, если силу увеличить в 2 раза? Коэффициент трения между бруском и столом равен 0,2.</p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "19-1.jpg"
                "alt" => null
                "width" => "1562"
                "height" => 352
                "path" => "/media/fizika_09/gendenshtejn-u/0-11/19-1.webp?ts=1759348238"
              ]
            ]
          ]
          #original: array:7 [
            "id" => 1696375
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1327}
            "task" => array:2 [
              "refs" => "1433634"
              "type" => "task"
            ]
            "text" => "<p><strong>19.</strong> Деревянный брусок движется с постоянной скоростью по столу под действием некоторой горизонтально направленной силы. С каким ускорением будет двигаться этот брусок, если силу увеличить в 2 раза? Коэффициент трения между бруском и столом равен 0,2.</p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "19-1.jpg"
                "alt" => null
                "width" => "1562"
                "height" => 352
                "path" => "/media/fizika_09/gendenshtejn-u/0-11/19-1.webp?ts=1759348238"
              ]
            ]
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        1 => App\Models\Element {#1325
          #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" => 1780445
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1335
              #items: array:1 [
                0 => App\Models\Edition {#1326
                  #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 [ …21]
                  #original: array:21 [ …21]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
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                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "1433634"
              "type" => "task"
            ]
            "text" => "<p><strong>Дано:</strong></p><p>$v_1 = \text{const}$ (начальная скорость постоянна)</p><p>$F_2 = 2F_1$ (силу увеличили в 2 раза)</p><p>$\mu = 0.2$</p><p><strong>Найти:</strong></p><p>$a - ?$ (ускорение)</p><p><strong>Решение:</strong></p><p>Рассмотрим движение бруска в двух ситуациях.</p><p><strong>1.</strong> Изначально брусок движется с постоянной скоростью ($v_1 = \text{const}$). Согласно первому закону Ньютона, это означает, что равнодействующая всех сил, приложенных к телу, равна нулю. В горизонтальном направлении на брусок действуют приложенная сила $F_1$ и сила трения скольжения $F_{тр}$, направленная в противоположную сторону. Следовательно, их модули равны:</p><p>$F_1 = F_{тр}$</p><p>Сила трения скольжения вычисляется по формуле $F_{тр} = \mu N$, где $\mu$ — коэффициент трения, а $\text{N}$ — сила нормальной реакции опоры. Так как движение происходит по горизонтальной поверхности, сила нормальной реакции опоры равна силе тяжести $mg$:</p><p>$N = mg$</p><p>Таким образом, начальная приложенная сила равна:</p><p>$F_1 = \mu mg$</p><p><strong>2.</strong> Затем приложенную силу увеличивают в 2 раза, и она становится равной $F_2 = 2F_1$. Теперь приложенная сила превышает силу трения, и брусок начинает двигаться с ускорением $\text{a}$. Согласно второму закону Ньютона, равнодействующая сил равна произведению массы тела на его ускорение:</p><p>$F_2 - F_{тр} = ma$</p><p>Сила трения скольжения $F_{тр}$ не изменилась, так как она зависит от $\mu$ и $\text{N}$, которые остались прежними. Подставим в уравнение выражения для $F_2$ и $F_{тр}$:</p><p>$2F_1 - \mu mg = ma$</p><p>Из первого случая мы знаем, что $F_1 = \mu mg$. Подставим это выражение в полученное уравнение:</p><p>$2(\mu mg) - \mu mg = ma$</p><p>Упростим левую часть:</p><p>$\mu mg = ma$</p><p>Масса бруска $\text{m}$ сокращается, и мы получаем выражение для ускорения:</p><p>$a = \mu g$</p><p>Примем ускорение свободного падения $g \approx 10 \, \text{м/с}^2$. Вычислим значение ускорения:</p><p>$a = 0.2 \cdot 10 \, \text{м/с}^2 = 2 \, \text{м/с}^2$</p><p><strong>Ответ:</strong> $2 \, \text{м/с}^2$.</p>"
          ]
          #original: array:6 [
            "id" => 1780445
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1335}
            "task" => array:2 [
              "refs" => "1433634"
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            "text" => "<p><strong>Дано:</strong></p><p>$v_1 = \text{const}$ (начальная скорость постоянна)</p><p>$F_2 = 2F_1$ (силу увеличили в 2 раза)</p><p>$\mu = 0.2$</p><p><strong>Найти:</strong></p><p>$a - ?$ (ускорение)</p><p><strong>Решение:</strong></p><p>Рассмотрим движение бруска в двух ситуациях.</p><p><strong>1.</strong> Изначально брусок движется с постоянной скоростью ($v_1 = \text{const}$). Согласно первому закону Ньютона, это означает, что равнодействующая всех сил, приложенных к телу, равна нулю. В горизонтальном направлении на брусок действуют приложенная сила $F_1$ и сила трения скольжения $F_{тр}$, направленная в противоположную сторону. Следовательно, их модули равны:</p><p>$F_1 = F_{тр}$</p><p>Сила трения скольжения вычисляется по формуле $F_{тр} = \mu N$, где $\mu$ — коэффициент трения, а $\text{N}$ — сила нормальной реакции опоры. Так как движение происходит по горизонтальной поверхности, сила нормальной реакции опоры равна силе тяжести $mg$:</p><p>$N = mg$</p><p>Таким образом, начальная приложенная сила равна:</p><p>$F_1 = \mu mg$</p><p><strong>2.</strong> Затем приложенную силу увеличивают в 2 раза, и она становится равной $F_2 = 2F_1$. Теперь приложенная сила превышает силу трения, и брусок начинает двигаться с ускорением $\text{a}$. Согласно второму закону Ньютона, равнодействующая сил равна произведению массы тела на его ускорение:</p><p>$F_2 - F_{тр} = ma$</p><p>Сила трения скольжения $F_{тр}$ не изменилась, так как она зависит от $\mu$ и $\text{N}$, которые остались прежними. Подставим в уравнение выражения для $F_2$ и $F_{тр}$:</p><p>$2F_1 - \mu mg = ma$</p><p>Из первого случая мы знаем, что $F_1 = \mu mg$. Подставим это выражение в полученное уравнение:</p><p>$2(\mu mg) - \mu mg = ma$</p><p>Упростим левую часть:</p><p>$\mu mg = ma$</p><p>Масса бруска $\text{m}$ сокращается, и мы получаем выражение для ускорения:</p><p>$a = \mu g$</p><p>Примем ускорение свободного падения $g \approx 10 \, \text{м/с}^2$. Вычислим значение ускорения:</p><p>$a = 0.2 \cdot 10 \, \text{м/с}^2 = 2 \, \text{м/с}^2$</p><p><strong>Ответ:</strong> $2 \, \text{м/с}^2$.</p>"
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№19 (с. 104)
Условие. №19 (с. 104)
скриншот условия
Физика, 9 класс Учебник, авторы: Генденштейн Лев Элевич, Булатова Альбина Александрова, Корнильев Игорь Николаевич, Кошкина Анжелика Васильевна, издательство Бином, Москва, 2016, бирюзового цвета, Часть 1, страница 104, номер 19, Условие

19. Деревянный брусок движется с постоянной скоростью по столу под действием некоторой горизонтально направленной силы. С каким ускорением будет двигаться этот брусок, если силу увеличить в 2 раза? Коэффициент трения между бруском и столом равен 0,2.

Решение. №19 (с. 104)

Дано:

$v_1 = \text{const}$ (начальная скорость постоянна)

$F_2 = 2F_1$ (силу увеличили в 2 раза)

$\mu = 0.2$

Найти:

$a - ?$ (ускорение)

Решение:

Рассмотрим движение бруска в двух ситуациях.

1. Изначально брусок движется с постоянной скоростью ($v_1 = \text{const}$). Согласно первому закону Ньютона, это означает, что равнодействующая всех сил, приложенных к телу, равна нулю. В горизонтальном направлении на брусок действуют приложенная сила $F_1$ и сила трения скольжения $F_{тр}$, направленная в противоположную сторону. Следовательно, их модули равны:

$F_1 = F_{тр}$

Сила трения скольжения вычисляется по формуле $F_{тр} = \mu N$, где $\mu$ — коэффициент трения, а $\text{N}$ — сила нормальной реакции опоры. Так как движение происходит по горизонтальной поверхности, сила нормальной реакции опоры равна силе тяжести $mg$:

$N = mg$

Таким образом, начальная приложенная сила равна:

$F_1 = \mu mg$

2. Затем приложенную силу увеличивают в 2 раза, и она становится равной $F_2 = 2F_1$. Теперь приложенная сила превышает силу трения, и брусок начинает двигаться с ускорением $\text{a}$. Согласно второму закону Ньютона, равнодействующая сил равна произведению массы тела на его ускорение:

$F_2 - F_{тр} = ma$

Сила трения скольжения $F_{тр}$ не изменилась, так как она зависит от $\mu$ и $\text{N}$, которые остались прежними. Подставим в уравнение выражения для $F_2$ и $F_{тр}$:

$2F_1 - \mu mg = ma$

Из первого случая мы знаем, что $F_1 = \mu mg$. Подставим это выражение в полученное уравнение:

$2(\mu mg) - \mu mg = ma$

Упростим левую часть:

$\mu mg = ma$

Масса бруска $\text{m}$ сокращается, и мы получаем выражение для ускорения:

$a = \mu g$

Примем ускорение свободного падения $g \approx 10 \, \text{м/с}^2$. Вычислим значение ускорения:

$a = 0.2 \cdot 10 \, \text{м/с}^2 = 2 \, \text{м/с}^2$

Ответ: $2 \, \text{м/с}^2$.

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