Номер 6, страница 241 - гдз по физике 8 класс учебник Изергин

Физика, 8 класс Учебник, автор: Изергин Эдуард Тимофеевич, издательство Русское слово, Москва, 2019

Авторы: Изергин Э. Т.

Тип: Учебник

Издательство: Русское слово

Год издания: 2019 - 2026

Цвет обложки: синий

ISBN: 978-5-533-01067-2

Глава V. Геометрическая оптика. Параграф 43. Формула тонкой линзы - номер 6, страница 241.

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" => 1492597
    "created_at" => "2026-04-10 13:58:26"
    "updated_at" => null
    "field_page_start" => "241"
    "field_page_end" => null
    "field_url" => "/8-klass/fizika/izergin-uchebnik/43-6"
    "field_display_title" => "6"
    "field_outside_task" => null
    "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: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #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"
              "field_creative_case" => "номером"
              "field_dative_case" => "номеру"
              "field_genitive_case" => "номера"
              "field_nominative_case" => "номер"
              "field_prepositional_case" => "номере"
            ]
            "field_short_name" => ""
          ]
          #original: 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"
              "field_creative_case" => "номером"
              "field_dative_case" => "номеру"
              "field_genitive_case" => "номера"
              "field_nominative_case" => "номер"
              "field_prepositional_case" => "номере"
            ]
            "field_short_name" => ""
          ]
          #changes: []
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          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
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          #dispatchesEvents: []
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          +timestamps: true
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          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "field_metatags_title" => null
    "field_metatags_description" => null
    "field_h1" => null
    "field_description_top" => null
    "field_description_bottom" => null
    "field_match" => null
    "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: []
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          #escapeWhenCastingToString: false
          #attributes: array:24 [
            "id" => 1492199
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Геометрическая оптика"
            "field_branch_order" => "V"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#333
              #items: array:1 [
                0 => App\Models\Term {#1033
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
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                  #withCount: []
                  +preventsLazyLoading: false
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                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:7 [
                    "id" => 29
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Глава"
                    "field_cases" => array:6 [
                      "field_accusative_case" => "Главу"
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                      "field_dative_case" => "Главе"
                      "field_genitive_case" => "Главы"
                      "field_nominative_case" => "Глава"
                      "field_prepositional_case" => "Главе"
                    ]
                    "field_page_check_not_needed" => null
                    "field_short_name" => null
                  ]
                  #original: array:7 [
                    "id" => 29
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Глава"
                    "field_cases" => array:6 [
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                    ]
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                  ]
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            "field_navigation_title" => null
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            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1030
              #items: array:1 [
                0 => App\Models\Book {#1032
                  #connection: "mysql"
                  #table: "books"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
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                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:50 [
                    "id" => 4168
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
                    "field_pages_status" => null
                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1034
                      #items: array:1 [
                        0 => App\Models\Term {#1035
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
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                          #escapeWhenCastingToString: false
                          #attributes: array:10 [
                            "id" => 6493
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Физика"
                            "field_abbreviated_name" => null
                            "field_cases" => array:6 [
                              "field_accusative_case" => "физику"
                              "field_creative_case" => "физикой"
                              "field_dative_case" => "физике"
                              "field_genitive_case" => "физики"
                              "field_nominative_case" => "физика"
                              "field_prepositional_case" => "физике"
                            ]
                            "field_foreign_lang_name" => null
                            "field_short_name" => null
                            "field_subject_type" => "technical_subject"
                            "field_translit" => "fizika"
                          ]
                          #original: array:10 [
                            "id" => 6493
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Физика"
                            "field_abbreviated_name" => null
                            "field_cases" => array:6 [
                              "field_accusative_case" => "физику"
                              "field_creative_case" => "физикой"
                              "field_dative_case" => "физике"
                              "field_genitive_case" => "физики"
                              "field_nominative_case" => "физика"
                              "field_prepositional_case" => "физике"
                            ]
                            "field_foreign_lang_name" => null
                            "field_short_name" => null
                            "field_subject_type" => "technical_subject"
                            "field_translit" => "fizika"
                          ]
                          #changes: []
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                          #attributeCastCache: []
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                          #touches: []
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                          #hidden: []
                          #visible: []
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                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1036
                      #items: array:1 [
                        0 => App\Models\Term {#1037
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
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                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 5457
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "8"
                            "field_cases" => array:6 [
                              "field_accusative_case" => "восьмой"
                              "field_creative_case" => "восьмым"
                              "field_dative_case" => "восьмому"
                              "field_genitive_case" => "восьмого"
                              "field_nominative_case" => "восьмой"
                              "field_prepositional_case" => "восьмом"
                            ]
                            "field_translit" => "vosmoj"
                          ]
                          #original: array:6 [
                            "id" => 5457
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "8"
                            "field_cases" => array:6 [
                              "field_accusative_case" => "восьмой"
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                              "field_dative_case" => "восьмому"
                              "field_genitive_case" => "восьмого"
                              "field_nominative_case" => "восьмой"
                              "field_prepositional_case" => "восьмом"
                            ]
                            "field_translit" => "vosmoj"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
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                          #touches: []
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                          #hidden: []
                          #visible: []
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                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #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"
                          +incrementing: false
                          #with: []
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                          #perPage: 15
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                          #attributes: array:6 [
                            "id" => 5176
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Русское слово"
                            "field_cases" => null
                            "field_translit" => "russkoe slovo"
                          ]
                          #original: array:6 [
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                    "field_author" => Illuminate\Database\Eloquent\Collection {#1040
                      #items: array:1 [
                        0 => App\Models\Term {#1041
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
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                          #attributes: array:12 [
                            "id" => 4491
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
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                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Эдуард"
                            "field_patronymic" => "Тимофеевич"
                            "field_surname_rp" => null
                          ]
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                            "id" => 4491
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
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                            "field_bio" => null
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                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Эдуард"
                            "field_patronymic" => "Тимофеевич"
                            "field_surname_rp" => null
                          ]
                          #changes: []
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                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1042
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                      #escapeWhenCastingToString: false
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                      #items: array:1 [
                        0 => App\Models\Term {#1044
                          #connection: "mysql"
                          #table: "terms"
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                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
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                            ]
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                      #items: array:1 [
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                          #classCastCache: []
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                          #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 {#1049
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1050
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1051
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1052
                      #items: array:1 [
                        0 => App\Models\Term {#1053
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:10 [
                            "id" => 6706
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "ФГОС (старый)"
                            "field_cases" => array:6 [
                              "field_accusative_case" => null
                              "field_creative_case" => null
                              "field_dative_case" => null
                              "field_genitive_case" => null
                              "field_nominative_case" => null
                              "field_prepositional_case" => null
                            ]
                            "field_color" => null
                            "field_end_year" => "2022"
                            "field_start_year" => "2019"
                            "field_translit" => "fgos-old"
                            "field_type" => null
                          ]
                          #original: array:10 [
                            "id" => 6706
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "ФГОС (старый)"
                            "field_cases" => array:6 [
                              "field_accusative_case" => null
                              "field_creative_case" => null
                              "field_dative_case" => null
                              "field_genitive_case" => null
                              "field_nominative_case" => null
                              "field_prepositional_case" => null
                            ]
                            "field_color" => null
                            "field_end_year" => "2022"
                            "field_start_year" => "2019"
                            "field_translit" => "fgos-old"
                            "field_type" => null
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_publication_number" => null
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1054
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1055
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => null
                    "field_publication_year" => "2019"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебник для 8 класса общеобразовательных организаций"
                    "field_allowed" => null
                    "field_reserve_field" => null
                    "field_link_to_source" => null
                    "field_tasks_count" => "417"
                    "field_priority" => null
                    "field_default_folder" => "/fizika_08/izergin-u/"
                    "field_isbn" => "978-5-533-01067-2"
                    "field_cover" => array:1 [
                      0 => "/media/fizika_08/izergin-u/covers/cover1.webp?ts=1760998278"
                    ]
                    "field_cover_alts" => array:1 [
                      0 => ""
                    ]
                    "field_covers" => array:1 [
                      0 => array:4 [
                        "path" => "/media/fizika_08/izergin-u/covers/cover1.webp?ts=1760998278"
                        "alt" => ""
                        "width" => "1608"
                        "height" => "2576"
                      ]
                    ]
                    "field_popular_book" => "0"
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1056
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1057
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1058
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_url" => "/8-klass/fizika/izergin-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1059
                      #items: array:1 [
                        0 => App\Models\Term {#1060
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 49
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "синий"
                            "field_cases" => array:6 [
                              "field_accusative_case" => null
                              "field_creative_case" => null
                              "field_dative_case" => null
                              "field_genitive_case" => null
                              "field_nominative_case" => null
                              "field_prepositional_case" => null
                            ]
                            "field_translit" => "siniy"
                          ]
                          #original: array:6 [
                            "id" => 49
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "синий"
                            "field_cases" => array:6 [
                              "field_accusative_case" => null
                              "field_creative_case" => null
                              "field_dative_case" => null
                              "field_genitive_case" => null
                              "field_nominative_case" => null
                              "field_prepositional_case" => null
                            ]
                            "field_translit" => "siniy"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [
                      "class" => 379
                      "subject" => 556
                      "class_subject" => 492
                    ]
                  ]
                  #original: array:50 [
                    "id" => 4168
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
                    "field_pages_status" => null
                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1034}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1036}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1038}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1040}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1042}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1043}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1045}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1047}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1049}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1050}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1051}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1052}
                    "field_publication_number" => null
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1054}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1055}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => null
                    "field_publication_year" => "2019"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебник для 8 класса общеобразовательных организаций"
                    "field_allowed" => null
                    "field_reserve_field" => null
                    "field_link_to_source" => null
                    "field_tasks_count" => "417"
                    "field_priority" => null
                    "field_default_folder" => "/fizika_08/izergin-u/"
                    "field_isbn" => "978-5-533-01067-2"
                    "field_cover" => array:1 [
                      0 => "/media/fizika_08/izergin-u/covers/cover1.webp?ts=1760998278"
                    ]
                    "field_cover_alts" => array:1 [
                      0 => ""
                    ]
                    "field_covers" => array:1 [
                      0 => array:4 [
                        "path" => "/media/fizika_08/izergin-u/covers/cover1.webp?ts=1760998278"
                        "alt" => ""
                        "width" => "1608"
                        "height" => "2576"
                      ]
                    ]
                    "field_popular_book" => "0"
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1056}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1057}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1058}
                    "field_url" => "/8-klass/fizika/izergin-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1059}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [
                      "class" => 379
                      "subject" => 556
                      "class_subject" => 492
                    ]
                  ]
                  #changes: []
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                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1061
              #items: []
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 1492199
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Геометрическая оптика"
            "field_branch_order" => "V"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#333}
            "field_page_start" => "211"
            "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 {#1030}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1061}
          ]
          #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 {#1062
      #items: array:2 [
        0 => App\Models\Branch {#1023}
        1 => App\Models\Branch {#1063
          #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" => 1492205
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Формула тонкой линзы"
            "field_branch_order" => "43"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1064
              #items: array:1 [
                0 => App\Models\Term {#1065
                  #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 [
                      "field_accusative_case" => "Параграф"
                      "field_creative_case" => "Параграфом"
                      "field_dative_case" => "Параграфу"
                      "field_genitive_case" => "Параграфа"
                      "field_nominative_case" => "Параграф"
                      "field_prepositional_case" => "Параграфе"
                    ]
                    "field_page_check_not_needed" => null
                    "field_short_name" => "§"
                  ]
                  #original: array:7 [
                    "id" => 32
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Параграф"
                    "field_cases" => array:6 [
                      "field_accusative_case" => "Параграф"
                      "field_creative_case" => "Параграфом"
                      "field_dative_case" => "Параграфу"
                      "field_genitive_case" => "Параграфа"
                      "field_nominative_case" => "Параграф"
                      "field_prepositional_case" => "Параграфе"
                    ]
                    "field_page_check_not_needed" => null
                    "field_short_name" => "§"
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "238"
            "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 {#1066
              #items: array:1 [
                0 => App\Models\Book {#1032}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1067
              #items: array:1 [
                0 => App\Models\Branch {#1068
                  #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" => 1492199
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_display_title" => "Геометрическая оптика"
                    "field_branch_order" => "V"
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1069
                      #items: array:1 [
                        0 => App\Models\Term {#1033}
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_page_start" => "211"
                    "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 {#1070
                      #items: array:1 [
                        0 => App\Models\Book {#1032}
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1071
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                  ]
                  #original: array:24 [
                    "id" => 1492199
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_display_title" => "Геометрическая оптика"
                    "field_branch_order" => "V"
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1069}
                    "field_page_start" => "211"
                    "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 {#1070}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1071}
                  ]
                  #changes: []
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                  #attributeCastCache: []
                  #dateFormat: null
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                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 1492205
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Формула тонкой линзы"
            "field_branch_order" => "43"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1064}
            "field_page_start" => "238"
            "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 {#1066}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1067}
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "content" => Illuminate\Database\Eloquent\Collection {#1072
      #items: array:2 [
        0 => App\Models\Element {#1073
          #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" => 1774740
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1074
              #items: array:1 [
                0 => App\Models\Edition {#1075
                  #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 [
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                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1077}
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                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1078}
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                  ]
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            "task" => array:2 [
              "refs" => "1492597"
              "type" => "task"
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            "text" => "<p><strong>6.</strong> Расстояние от свечи до линзы равно 30 см, а расстояние от линзы до экрана — 23 см. Какова оптическая сила линзы?</p>"
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                "width" => "1399"
                "height" => 239
                "path" => "/media/fizika_08/izergin-u/0-43/6-1.webp?ts=1761329271"
              ]
            ]
          ]
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            "id" => 1774740
            "created_at" => "2026-04-10 13:58:26"
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            "edition" => Illuminate\Database\Eloquent\Collection {#1074}
            "task" => array:2 [
              "refs" => "1492597"
              "type" => "task"
            ]
            "text" => "<p><strong>6.</strong> Расстояние от свечи до линзы равно 30 см, а расстояние от линзы до экрана — 23 см. Какова оптическая сила линзы?</p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "6-1.jpg"
                "alt" => null
                "width" => "1399"
                "height" => 239
                "path" => "/media/fizika_08/izergin-u/0-43/6-1.webp?ts=1761329271"
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        }
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          #table: "elements"
          #primaryKey: "id"
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            "created_at" => "2026-04-10 13:58:26"
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                  #attributes: array:21 [
                    "id" => 7014
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение"
                    "field_order" => "2"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1083
                      #items: array:1 [
                        0 => App\Models\Term {#1084
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
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                          #perPage: 15
                          +exists: true
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                          #attributes: array:6 [ …6]
                          #original: array:6 [ …6]
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                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1085
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                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1087
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                    "id" => 7014
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение"
                    "field_order" => "2"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1083}
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                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1085}
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                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1086}
                    "field_process_formula" => "katex"
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                  ]
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            "task" => array:2 [
              "refs" => "1492597"
              "type" => "task"
            ]
            "text" => "<p><strong>Дано:</strong></p><p>Расстояние от свечи до линзы $d = 30$ см</p><p>Расстояние от линзы до экрана $f = 23$ см</p><p>$d = 0,3$ м</p><p>$f = 0,23$ м</p><p><strong>Найти:</strong></p><p>Оптическую силу линзы $\text{D}$ - ?</p><p><strong>Решение:</strong></p><p>Оптическая сила линзы $\text{D}$ — это величина, обратная её фокусному расстоянию $\text{F}$, выраженному в метрах: $D = \frac{1}{F}$.</p><p>Фокусное расстояние линзы можно найти с помощью формулы тонкой линзы, которая связывает расстояние от предмета до линзы $\text{d}$ и расстояние от линзы до изображения $\text{f}$:</p><p>$\frac{1}{d} + \frac{1}{f} = \frac{1}{F}$</p><p>Так как на экране получается изображение, оно является действительным, поэтому линза — собирающая, а расстояние $\text{f}$ берется со знаком «+».</p><p>Объединив две формулы, получаем выражение для оптической силы:</p><p>$D = \frac{1}{d} + \frac{1}{f}$</p><p>Подставим значения в систему СИ (метры):</p><p>$D = \frac{1}{0,3 \text{ м}} + \frac{1}{0,23 \text{ м}}$</p><p>Приведем дроби к общему знаменателю и выполним сложение:</p><p>$D = \frac{1}{0,3} + \frac{1}{0,23} = \frac{0,23 + 0,3}{0,3 \cdot 0,23} = \frac{0,53}{0,069} \approx 7,681$ дптр</p><p>Округлим результат до сотых.</p><p>$D \approx 7,68$ дптр</p><p><strong>Ответ:</strong> оптическая сила линзы примерно равна $7,68$ дптр.</p>"
          ]
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            "id" => 1851912
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1081}
            "task" => array:2 [
              "refs" => "1492597"
              "type" => "task"
            ]
            "text" => "<p><strong>Дано:</strong></p><p>Расстояние от свечи до линзы $d = 30$ см</p><p>Расстояние от линзы до экрана $f = 23$ см</p><p>$d = 0,3$ м</p><p>$f = 0,23$ м</p><p><strong>Найти:</strong></p><p>Оптическую силу линзы $\text{D}$ - ?</p><p><strong>Решение:</strong></p><p>Оптическая сила линзы $\text{D}$ — это величина, обратная её фокусному расстоянию $\text{F}$, выраженному в метрах: $D = \frac{1}{F}$.</p><p>Фокусное расстояние линзы можно найти с помощью формулы тонкой линзы, которая связывает расстояние от предмета до линзы $\text{d}$ и расстояние от линзы до изображения $\text{f}$:</p><p>$\frac{1}{d} + \frac{1}{f} = \frac{1}{F}$</p><p>Так как на экране получается изображение, оно является действительным, поэтому линза — собирающая, а расстояние $\text{f}$ берется со знаком «+».</p><p>Объединив две формулы, получаем выражение для оптической силы:</p><p>$D = \frac{1}{d} + \frac{1}{f}$</p><p>Подставим значения в систему СИ (метры):</p><p>$D = \frac{1}{0,3 \text{ м}} + \frac{1}{0,23 \text{ м}}$</p><p>Приведем дроби к общему знаменателю и выполним сложение:</p><p>$D = \frac{1}{0,3} + \frac{1}{0,23} = \frac{0,23 + 0,3}{0,3 \cdot 0,23} = \frac{0,53}{0,069} \approx 7,681$ дптр</p><p>Округлим результат до сотых.</p><p>$D \approx 7,68$ дптр</p><p><strong>Ответ:</strong> оптическая сила линзы примерно равна $7,68$ дптр.</p>"
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    "page" => Illuminate\Database\Eloquent\Collection {#1553
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                    "created_at" => "2026-04-10 13:58:26"
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                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1098
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                          #attributes: array:10 [ …10]
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                        0 => App\Models\Term {#1101
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
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                          +exists: true
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                          #escapeWhenCastingToString: false
                          #attributes: array:6 [ …6]
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                          #guarded: array:1 [ …1]
                        }
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                        0 => App\Models\Term {#1103
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
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                          +exists: true
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                          #escapeWhenCastingToString: false
                           …18
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                    "field_isbn" => "978-5-533-01067-2"
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                      ]
                    ]
                    "field_popular_book" => "0"
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                      #items: []
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                      #items: []
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                    }
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                    "field_url" => "/8-klass/fizika/izergin-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1123
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                    "field_metatags_title" => null
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                    "breadcrumbs" => array:3 [
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                3 => App\Models\Task {#1422
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}
№6 (с. 241)
Условие. №6 (с. 241)
скриншот условия
Физика, 8 класс Учебник, автор: Изергин Эдуард Тимофеевич, издательство Русское слово, Москва, 2019, страница 241, номер 6, Условие

6. Расстояние от свечи до линзы равно 30 см, а расстояние от линзы до экрана — 23 см. Какова оптическая сила линзы?

Решение. №6 (с. 241)

Дано:

Расстояние от свечи до линзы $d = 30$ см

Расстояние от линзы до экрана $f = 23$ см

$d = 0,3$ м

$f = 0,23$ м

Найти:

Оптическую силу линзы $\text{D}$ - ?

Решение:

Оптическая сила линзы $\text{D}$ — это величина, обратная её фокусному расстоянию $\text{F}$, выраженному в метрах: $D = \frac{1}{F}$.

Фокусное расстояние линзы можно найти с помощью формулы тонкой линзы, которая связывает расстояние от предмета до линзы $\text{d}$ и расстояние от линзы до изображения $\text{f}$:

$\frac{1}{d} + \frac{1}{f} = \frac{1}{F}$

Так как на экране получается изображение, оно является действительным, поэтому линза — собирающая, а расстояние $\text{f}$ берется со знаком «+».

Объединив две формулы, получаем выражение для оптической силы:

$D = \frac{1}{d} + \frac{1}{f}$

Подставим значения в систему СИ (метры):

$D = \frac{1}{0,3 \text{ м}} + \frac{1}{0,23 \text{ м}}$

Приведем дроби к общему знаменателю и выполним сложение:

$D = \frac{1}{0,3} + \frac{1}{0,23} = \frac{0,23 + 0,3}{0,3 \cdot 0,23} = \frac{0,53}{0,069} \approx 7,681$ дптр

Округлим результат до сотых.

$D \approx 7,68$ дптр

Ответ: оптическая сила линзы примерно равна $7,68$ дптр.

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