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Номер 47, страница 269 - гдз по физике 8 класс учебник Громов, Родина
Авторы: Громов С. В., Родина Н. А., Белага В. В., Ломаченков И. А., Панебратцев Ю. А.
Тип: Учебник
Серия: классический курс
Издательство: Просвещение
Год издания: 2018 - 2026
Цвет обложки: синий
ISBN: 978-5-09-052825-2
Популярные ГДЗ в 8 классе
Задачи и упражнения - номер 47, страница 269.
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"field_cover_color" => Illuminate\Database\Eloquent\Collection {#1071 …2} "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "breadcrumbs" => array:3 [ …3] ] #original: array:50 [ "id" => 3654 "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 {#1041 …2} "field_class" => Illuminate\Database\Eloquent\Collection {#1043 …2} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1045 …2} "field_author" => Illuminate\Database\Eloquent\Collection {#1047 …2} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1053 …2} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1054 …2} "field_country" => Illuminate\Database\Eloquent\Collection {#1056 …2} "field_city" => Illuminate\Database\Eloquent\Collection {#1058 …2} 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"field_isbn" => "978-5-09-052825-2" "field_cover" => array:1 [ …1] "field_cover_alts" => array:1 [ …1] "field_covers" => array:1 [ …1] "field_popular_book" => "0" "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1068 …2} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1069 …2} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1070 …2} "field_url" => "/8-klass/fizika/gromov-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1071 …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: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "branch_parent" => Illuminate\Database\Eloquent\Collection {#1073 #items: [] #escapeWhenCastingToString: false } ] #original: array:24 [ "id" => 1612241 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "Задачи и упражнения" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1039} "field_page_start" => "266" "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 {#1038} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1073} ] #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 {#1074 #items: array:1 [ 0 => App\Models\Branch {#1034} ] #escapeWhenCastingToString: false } "content" => Illuminate\Database\Eloquent\Collection {#1077 #items: array:2 [ 0 => App\Models\Element {#1086 #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" => 1850640 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1095 #items: array:1 [ 0 => App\Models\Edition {#1087 #connection: "mysql" #table: "editions" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:21 [ "id" => 6892 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Условие" "field_order" => "1" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1089 …2} "field_content_type" => "free" "field_content_mode" => "text, image" "field_page_content_mode" => "image" "field_content_text_checked" => "0" "field_page_content_text_checked" => "0" "field_solution_author" => "Автор" "field_moderator" => "stas" "field_edition_type" => "statement" "field_root_dir" => "0-" "field_responsible" => Illuminate\Database\Eloquent\Collection {#1090 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1091 …2} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1092 …2} "field_content_source" => null ] #original: array:21 [ "id" => 6892 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Условие" "field_order" => "1" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1089 …2} "field_content_type" => "free" "field_content_mode" => "text, image" "field_page_content_mode" => "image" "field_content_text_checked" => "0" "field_page_content_text_checked" => "0" "field_solution_author" => "Автор" "field_moderator" => "stas" "field_edition_type" => "statement" "field_root_dir" => "0-" "field_responsible" => Illuminate\Database\Eloquent\Collection {#1090 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1091 …2} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1092 …2} "field_content_source" => null ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "task" => array:2 [ "refs" => "1612914" "type" => "task" ] "text" => "<p><strong>47.</strong> Рассчитайте количество теплоты, которое выделяется или поглощается в процессах, перечисленных в задаче <strong>39.</strong> Масса тела во всех случаях равна 2 кг.</p>" "img" => array:1 [ 0 => array:5 [ "name" => "47-1.jpg" "alt" => null "width" => "1661" "height" => 266 "path" => "/media/fizika_08/gromov-u/0-upr/47-1.webp?ts=1763478081" ] ] ] #original: array:7 [ "id" => 1850640 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1095} "task" => array:2 [ "refs" => "1612914" "type" => "task" ] "text" => "<p><strong>47.</strong> Рассчитайте количество теплоты, которое выделяется или поглощается в процессах, перечисленных в задаче <strong>39.</strong> Масса тела во всех случаях равна 2 кг.</p>" "img" => array:1 [ 0 => array:5 [ "name" => "47-1.jpg" "alt" => null "width" => "1661" "height" => 266 "path" => "/media/fizika_08/gromov-u/0-upr/47-1.webp?ts=1763478081" ] ] ] #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 {#1093 #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" => 1900701 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1103 #items: array:1 [ 0 => App\Models\Edition {#1094 #connection: "mysql" #table: "editions" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:21 [ "id" => 7854 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Решение" "field_order" => "2" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1097 …2} "field_content_type" => "free" "field_content_mode" => "text" "field_page_content_mode" => "" "field_content_text_checked" => "0" "field_page_content_text_checked" => "0" "field_solution_author" => "Gemini 2.5 Pro" "field_moderator" => "tolik" "field_edition_type" => "solution" "field_root_dir" => "1-" "field_responsible" => Illuminate\Database\Eloquent\Collection {#1098 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1099 …2} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1100 …2} "field_content_source" => null ] #original: array:21 [ "id" => 7854 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Решение" "field_order" => "2" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1097 …2} "field_content_type" => "free" "field_content_mode" => "text" "field_page_content_mode" => "" "field_content_text_checked" => "0" "field_page_content_text_checked" => "0" "field_solution_author" => "Gemini 2.5 Pro" "field_moderator" => "tolik" "field_edition_type" => "solution" "field_root_dir" => "1-" "field_responsible" => Illuminate\Database\Eloquent\Collection {#1098 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1099 …2} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1100 …2} "field_content_source" => null ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "task" => array:2 [ "refs" => "1612914" "type" => "task" ] "text" => "<p>Поскольку условие задачи 39 не предоставлено, произведем расчеты для нескольких типовых тепловых процессов. Для всех расчетов будем использовать справочные значения физических величин.</p><p><strong>Дано:</strong></p><p>Масса тела, $m = 2$ кг</p><p><strong>Найти:</strong></p><p>Количество теплоты $\text{Q}$ для каждого процесса.</p><p><strong>Решение:</strong></p><p><strong>а) Нагревание стального бруска от 20 °С до 520 °С.</strong></p><p>Количество теплоты, необходимое для нагревания тела (или выделяющееся при его охлаждении), рассчитывается по формуле:</p><p>$Q = c \cdot m \cdot (t_2 - t_1)$</p><p>где $\text{c}$ – удельная теплоемкость вещества, $\text{m}$ – масса тела, $t_1$ и $t_2$ – начальная и конечная температуры. Удельная теплоемкость стали $c_{стали} \approx 500 \frac{Дж}{кг \cdot °С}$.</p><p>В данном случае температура тела повышается, значит, теплота поглощается ($Q > 0$).</p><p>$Q_а = 500 \frac{Дж}{кг \cdot °С} \cdot 2 \, кг \cdot (520 \, °С - 20 \, °С) = 1000 \cdot 500 = 500000 \, Дж = 500 \, кДж$.</p><p><strong>Ответ:</strong> поглощается 500 кДж теплоты.</p><p><strong>б) Плавление льда при температуре 0 °С.</strong></p><p>Количество теплоты, необходимое для плавления вещества, находящегося при температуре плавления, рассчитывается по формуле:</p><p>$Q = \lambda \cdot m$</p><p>где $\lambda$ – удельная теплота плавления. Удельная теплота плавления льда $\lambda_{льда} = 3.3 \cdot 10^5 \frac{Дж}{кг}$.</p><p>Плавление – это процесс, при котором теплота поглощается.</p><p>$Q_б = 3.3 \cdot 10^5 \frac{Дж}{кг} \cdot 2 \, кг = 6.6 \cdot 10^5 \, Дж = 660 \, кДж$.</p><p><strong>Ответ:</strong> поглощается 660 кДж теплоты.</p><p><strong>в) Парообразование воды при температуре 100 °С.</strong></p><p>Количество теплоты, необходимое для превращения жидкости в пар при температуре кипения, рассчитывается по формуле:</p><p>$Q = L \cdot m$</p><p>где $\text{L}$ – удельная теплота парообразования. Удельная теплота парообразования воды $L_{воды} = 2.3 \cdot 10^6 \frac{Дж}{кг}$.</p><p>Парообразование – это процесс, при котором теплота поглощается.</p><p>$Q_в = 2.3 \cdot 10^6 \frac{Дж}{кг} \cdot 2 \, кг = 4.6 \cdot 10^6 \, Дж = 4.6 \, МДж$.</p><p><strong>Ответ:</strong> поглощается 4.6 МДж теплоты.</p><p><strong>г) Охлаждение кирпича от 100 °С до 20 °С.</strong></p><p>Используем формулу для расчета количества теплоты при изменении температуры:</p><p>$Q = c \cdot m \cdot (t_2 - t_1)$</p><p>Удельная теплоемкость кирпича $c_{кирпича} \approx 880 \frac{Дж}{кг \cdot °С}$.</p><p>В данном случае температура тела понижается, значит, теплота выделяется ($Q < 0$).</p><p>$Q_г = 880 \frac{Дж}{кг \cdot °С} \cdot 2 \, кг \cdot (20 \, °С - 100 \, °С) = 1760 \cdot (-80) = -140800 \, Дж = -140.8 \, кДж$.</p><p>Знак "минус" указывает на то, что теплота выделяется.</p><p><strong>Ответ:</strong> выделяется 140.8 кДж теплоты.</p><p><strong>д) Кристаллизация свинца при температуре плавления (327 °С).</strong></p><p>Количество теплоты, выделяющееся при кристаллизации (затвердевании) вещества, рассчитывается по формуле:</p><p>$Q = -\lambda \cdot m$</p><p>Удельная теплота плавления свинца $\lambda_{свинца} = 2.5 \cdot 10^4 \frac{Дж}{кг}$.</p><p>Кристаллизация – это процесс, при котором теплота выделяется.</p><p>$Q_д = -2.5 \cdot 10^4 \frac{Дж}{кг} \cdot 2 \, кг = -5 \cdot 10^4 \, Дж = -50 \, кДж$.</p><p><strong>Ответ:</strong> выделяется 50 кДж теплоты.</p>" ] #original: array:6 [ "id" => 1900701 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1103} "task" => array:2 [ "refs" => "1612914" "type" => "task" ] "text" => "<p>Поскольку условие задачи 39 не предоставлено, произведем расчеты для нескольких типовых тепловых процессов. Для всех расчетов будем использовать справочные значения физических величин.</p><p><strong>Дано:</strong></p><p>Масса тела, $m = 2$ кг</p><p><strong>Найти:</strong></p><p>Количество теплоты $\text{Q}$ для каждого процесса.</p><p><strong>Решение:</strong></p><p><strong>а) Нагревание стального бруска от 20 °С до 520 °С.</strong></p><p>Количество теплоты, необходимое для нагревания тела (или выделяющееся при его охлаждении), рассчитывается по формуле:</p><p>$Q = c \cdot m \cdot (t_2 - t_1)$</p><p>где $\text{c}$ – удельная теплоемкость вещества, $\text{m}$ – масса тела, $t_1$ и $t_2$ – начальная и конечная температуры. Удельная теплоемкость стали $c_{стали} \approx 500 \frac{Дж}{кг \cdot °С}$.</p><p>В данном случае температура тела повышается, значит, теплота поглощается ($Q > 0$).</p><p>$Q_а = 500 \frac{Дж}{кг \cdot °С} \cdot 2 \, кг \cdot (520 \, °С - 20 \, °С) = 1000 \cdot 500 = 500000 \, Дж = 500 \, кДж$.</p><p><strong>Ответ:</strong> поглощается 500 кДж теплоты.</p><p><strong>б) Плавление льда при температуре 0 °С.</strong></p><p>Количество теплоты, необходимое для плавления вещества, находящегося при температуре плавления, рассчитывается по формуле:</p><p>$Q = \lambda \cdot m$</p><p>где $\lambda$ – удельная теплота плавления. Удельная теплота плавления льда $\lambda_{льда} = 3.3 \cdot 10^5 \frac{Дж}{кг}$.</p><p>Плавление – это процесс, при котором теплота поглощается.</p><p>$Q_б = 3.3 \cdot 10^5 \frac{Дж}{кг} \cdot 2 \, кг = 6.6 \cdot 10^5 \, Дж = 660 \, кДж$.</p><p><strong>Ответ:</strong> поглощается 660 кДж теплоты.</p><p><strong>в) Парообразование воды при температуре 100 °С.</strong></p><p>Количество теплоты, необходимое для превращения жидкости в пар при температуре кипения, рассчитывается по формуле:</p><p>$Q = L \cdot m$</p><p>где $\text{L}$ – удельная теплота парообразования. Удельная теплота парообразования воды $L_{воды} = 2.3 \cdot 10^6 \frac{Дж}{кг}$.</p><p>Парообразование – это процесс, при котором теплота поглощается.</p><p>$Q_в = 2.3 \cdot 10^6 \frac{Дж}{кг} \cdot 2 \, кг = 4.6 \cdot 10^6 \, Дж = 4.6 \, МДж$.</p><p><strong>Ответ:</strong> поглощается 4.6 МДж теплоты.</p><p><strong>г) Охлаждение кирпича от 100 °С до 20 °С.</strong></p><p>Используем формулу для расчета количества теплоты при изменении температуры:</p><p>$Q = c \cdot m \cdot (t_2 - t_1)$</p><p>Удельная теплоемкость кирпича $c_{кирпича} \approx 880 \frac{Дж}{кг \cdot °С}$.</p><p>В данном случае температура тела понижается, значит, теплота выделяется ($Q < 0$).</p><p>$Q_г = 880 \frac{Дж}{кг \cdot °С} \cdot 2 \, кг \cdot (20 \, °С - 100 \, °С) = 1760 \cdot (-80) = -140800 \, Дж = -140.8 \, кДж$.</p><p>Знак "минус" указывает на то, что теплота выделяется.</p><p><strong>Ответ:</strong> выделяется 140.8 кДж теплоты.</p><p><strong>д) Кристаллизация свинца при температуре плавления (327 °С).</strong></p><p>Количество теплоты, выделяющееся при кристаллизации (затвердевании) вещества, рассчитывается по формуле:</p><p>$Q = -\lambda \cdot m$</p><p>Удельная теплота плавления свинца $\lambda_{свинца} = 2.5 \cdot 10^4 \frac{Дж}{кг}$.</p><p>Кристаллизация – это процесс, при котором теплота выделяется.</p><p>$Q_д = -2.5 \cdot 10^4 \frac{Дж}{кг} \cdot 2 \, кг = -5 \cdot 10^4 \, Дж = -50 \, кДж$.</p><p><strong>Ответ:</strong> выделяется 50 кДж теплоты.</p>" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "next" => array:2 [ "refs" => "1612915" "type" => "task" ] "previous" => array:2 [ "refs" => "1612913" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1129 #items: array:1 [ 0 => 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"uchebnik" ] #original: array:10 [ "id" => 6671 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Учебник" "field_book_type_foreign" => null "field_cases" => array:6 [ …6] "field_plural_form" => null "field_short_name" => null "field_short_name_foreign" => null "field_translit" => "uchebnik" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_country" => Illuminate\Database\Eloquent\Collection {#1110 #items: array:1 [ 0 => App\Models\Term {#1111 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 9 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Россия" "field_cases" => array:6 [ …6] "field_translit" => "rossiya" ] #original: array:6 [ "id" => 9 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Россия" "field_cases" => array:6 [ …6] "field_translit" => "rossiya" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_city" => Illuminate\Database\Eloquent\Collection {#1112 #items: array:1 [ 0 => App\Models\Term {#1113 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 15 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Москва" "field_cases" => array:6 [ …6] "field_translit" => "moskva" ] #original: array:6 [ "id" => 15 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Москва" "field_cases" => array:6 [ …6] "field_translit" => "moskva" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_series" => Illuminate\Database\Eloquent\Collection {#1114 #items: array:1 [ 0 => App\Models\Term {#1115 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:8 [ "id" => 4718 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "классический курс" "field_cases" => null "field_foreign_lang_series" => null "field_transcription_eng" => null "field_translit" => "klassicheskiy kurs" ] #original: array:8 [ "id" => 4718 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "классический курс" "field_cases" => null "field_foreign_lang_series" => null "field_transcription_eng" => null "field_translit" => "klassicheskiy kurs" ] #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_umk" => Illuminate\Database\Eloquent\Collection {#1116 #items: [] #escapeWhenCastingToString: false } "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1117 #items: [] #escapeWhenCastingToString: false } "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1118 #items: array:1 [ 0 => App\Models\Term {#1119 #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 [ …6] "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 [ …6] "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 {#1120 #items: [] #escapeWhenCastingToString: false } "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1121 #items: array:1 [ 0 => App\Models\Term {#1106} ] #escapeWhenCastingToString: false } "field_under_the_edition_degree" => null "field_cover_description" => null "field_publication_year" => "2018" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебное пособие для общеобразовательных организаций" "field_allowed" => null "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "830" "field_priority" => null "field_default_folder" => "/fizika_08/gromov-u/" "field_isbn" => "978-5-09-052825-2" "field_cover" => array:1 [ 0 => "/media/fizika_08/gromov-u/covers/cover1.webp?ts=1763397517" ] "field_cover_alts" => array:1 [ 0 => "" ] "field_covers" => array:1 [ 0 => array:4 [ "path" => "/media/fizika_08/gromov-u/covers/cover1.webp?ts=1763397517" "alt" => "" "width" => "1881" "height" => "2469" ] ] "field_popular_book" => "0" "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1122 #items: [] #escapeWhenCastingToString: false } "field_new_book" => Illuminate\Database\Eloquent\Collection {#1123 #items: [] #escapeWhenCastingToString: false } "field_old_book" => Illuminate\Database\Eloquent\Collection {#1124 #items: [] #escapeWhenCastingToString: false } "field_url" => "/8-klass/fizika/gromov-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1125 #items: array:1 [ 0 => App\Models\Term {#1126 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:6 [ "id" => 49 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "синий" "field_cases" => array:6 [ …6] "field_translit" => "siniy" ] #original: array:6 [ "id" => 49 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "синий" "field_cases" => array:6 [ …6] "field_translit" => "siniy" ] #changes: [] #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" => 3654 "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 {#1075} "field_class" => Illuminate\Database\Eloquent\Collection {#1085} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1079} "field_author" => Illuminate\Database\Eloquent\Collection {#1080} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1107} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1108} "field_country" => Illuminate\Database\Eloquent\Collection {#1110} "field_city" => Illuminate\Database\Eloquent\Collection {#1112} "field_series" => Illuminate\Database\Eloquent\Collection {#1114} "field_umk" => Illuminate\Database\Eloquent\Collection {#1116} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1117} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1118} "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1120} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1121} "field_under_the_edition_degree" => null "field_cover_description" => null "field_publication_year" => "2018" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебное пособие для общеобразовательных организаций" "field_allowed" => null "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "830" "field_priority" => null "field_default_folder" => "/fizika_08/gromov-u/" "field_isbn" => "978-5-09-052825-2" "field_cover" => array:1 [ 0 => "/media/fizika_08/gromov-u/covers/cover1.webp?ts=1763397517" ] "field_cover_alts" => array:1 [ 0 => "" ] "field_covers" => array:1 [ 0 => array:4 [ "path" => "/media/fizika_08/gromov-u/covers/cover1.webp?ts=1763397517" "alt" => "" "width" => "1881" "height" => "2469" ] ] "field_popular_book" => "0" "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1122} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1123} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1124} "field_url" => "/8-klass/fizika/gromov-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1125} "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: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "page" => Illuminate\Database\Eloquent\Collection {#1134 #items: array:1 [ 0 => App\Models\BookPage {#1133 #connection: "mysql" #table: "book_pages" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:21 [ "id" => 1613342 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_url" => "/8-klass/fizika/gromov-uchebnik/page-269" "field_display_title" => "269" "field_folder" => "1" "field_image_name" => "269" "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1135 #items: [] #escapeWhenCastingToString: false } "field_weight" => "0" "field_book_parent" => Illuminate\Database\Eloquent\Collection {#1136 #items: array:1 [ 0 => App\Models\Book {#1083} ] #escapeWhenCastingToString: false } "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "edition_groups" => Illuminate\Database\Eloquent\Collection {#1137 #items: [] #escapeWhenCastingToString: false } "content" => Illuminate\Database\Eloquent\Collection {#1147 #items: array:1 [ 0 => App\Models\Element {#1146 #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" => 1851053 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1148 …2} "book_page" => array:2 [ …2] "img" => array:1 [ …1] ] #original: array:6 [ "id" => 1851053 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1148 …2} "book_page" => array:2 [ …2] "img" => array:1 [ …1] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "next" => array:2 [ "refs" => "1613343" "type" => "book_page" ] "previous" => array:2 [ "refs" => "1613341" "type" => "book_page" ] "tasks" => Illuminate\Database\Eloquent\Collection {#1237 #items: array:11 [ 0 => App\Models\Task {#1255 #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" => 1612905 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-38" "field_display_title" => "38" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1256 …2} "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 {#1257 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1258 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1259 …2} "content" => Illuminate\Database\Eloquent\Collection {#1261 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1267 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1612905 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-38" "field_display_title" => "38" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1256 …2} "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 {#1257 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1258 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1259 …2} "content" => Illuminate\Database\Eloquent\Collection {#1261 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1267 …2} "page" => array:2 [ …2] ] #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\Task {#1262 #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" => 1612906 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-39" "field_display_title" => "39" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1260 …2} "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 {#1269 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1265 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1263 …2} "content" => Illuminate\Database\Eloquent\Collection {#1264 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1279 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1612906 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-39" "field_display_title" => "39" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1260 …2} "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 {#1269 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1265 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1263 …2} "content" => Illuminate\Database\Eloquent\Collection {#1264 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1279 …2} "page" => array:2 [ …2] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 2 => App\Models\Task {#1274 #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" => 1612907 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-40" "field_display_title" => "40" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1266 …2} "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 {#1281 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1277 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1275 …2} "content" => Illuminate\Database\Eloquent\Collection {#1276 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1291 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1612907 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-40" "field_display_title" => "40" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1266 …2} "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 {#1281 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1277 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1275 …2} "content" => Illuminate\Database\Eloquent\Collection {#1276 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1291 …2} "page" => array:2 [ …2] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 3 => App\Models\Task {#1286 #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" => 1612908 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-41" "field_display_title" => "41" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1278 …2} "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 {#1293 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1289 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1287 …2} "content" => Illuminate\Database\Eloquent\Collection {#1288 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1303 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1612908 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-41" "field_display_title" => "41" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1278 …2} "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 {#1293 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1289 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1287 …2} "content" => Illuminate\Database\Eloquent\Collection {#1288 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1303 …2} "page" => array:2 [ …2] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 4 => App\Models\Task {#1298 #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" => 1612909 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-42" "field_display_title" => "42" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1290 …2} "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 {#1305 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1301 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1299 …2} "content" => Illuminate\Database\Eloquent\Collection {#1300 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1315 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1612909 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-42" "field_display_title" => "42" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1290 …2} "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 {#1305 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1301 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1299 …2} "content" => Illuminate\Database\Eloquent\Collection {#1300 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1315 …2} "page" => array:2 [ …2] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 5 => App\Models\Task {#1310 #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" => 1612910 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-43" "field_display_title" => "43" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1302 …2} "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 {#1317 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1313 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1311 …2} "content" => Illuminate\Database\Eloquent\Collection {#1312 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1327 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1612910 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-43" "field_display_title" => "43" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1302 …2} "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 {#1317 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1313 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1311 …2} "content" => Illuminate\Database\Eloquent\Collection {#1312 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1327 …2} "page" => array:2 [ …2] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 6 => App\Models\Task {#1322 #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" => 1612911 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-44" "field_display_title" => "44" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1314 …2} "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 {#1329 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1325 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1323 …2} "content" => Illuminate\Database\Eloquent\Collection {#1324 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1339 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1612911 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-44" "field_display_title" => "44" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1314 …2} "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 {#1329 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1325 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1323 …2} "content" => Illuminate\Database\Eloquent\Collection {#1324 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1339 …2} "page" => array:2 [ …2] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 7 => App\Models\Task {#1334 #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" => 1612912 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-45" "field_display_title" => "45" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1326 …2} "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 {#1341 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1337 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1335 …2} "content" => Illuminate\Database\Eloquent\Collection {#1336 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1351 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1612912 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-45" "field_display_title" => "45" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1326 …2} "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 {#1341 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1337 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1335 …2} "content" => Illuminate\Database\Eloquent\Collection {#1336 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1351 …2} "page" => array:2 [ …2] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 8 => App\Models\Task {#1346 #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" => 1612913 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-46" "field_display_title" => "46" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1338 …2} "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 {#1353 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1349 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1347 …2} "content" => Illuminate\Database\Eloquent\Collection {#1348 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1363 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1612913 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-46" "field_display_title" => "46" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1338 …2} "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 {#1353 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1349 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1347 …2} "content" => Illuminate\Database\Eloquent\Collection {#1348 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1363 …2} "page" => array:2 [ …2] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 9 => App\Models\Task {#1358 #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" => 1612914 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-47" "field_display_title" => "47" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1350 …2} "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 {#1365 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1361 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1359 …2} "content" => Illuminate\Database\Eloquent\Collection {#1362 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1360 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1612914 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-47" "field_display_title" => "47" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1350 …2} "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 {#1365 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1361 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1359 …2} "content" => Illuminate\Database\Eloquent\Collection {#1362 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1360 …2} "page" => array:2 [ …2] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 10 => App\Models\Task {#1370 #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" => 1612915 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-48" "field_display_title" => "48" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1371 …2} "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 {#1372 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1373 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1374 …2} "content" => Illuminate\Database\Eloquent\Collection {#1376 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1382 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1612915 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null …19 ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ …1] } ] #escapeWhenCastingToString: false } ] #original: array:21 [ "id" => 1613342 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_url" => "/8-klass/fizika/gromov-uchebnik/page-269" "field_display_title" => "269" "field_folder" => "1" "field_image_name" => "269" "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1135} "field_weight" => "0" "field_book_parent" => Illuminate\Database\Eloquent\Collection {#1136} "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "edition_groups" => Illuminate\Database\Eloquent\Collection {#1137} "content" => Illuminate\Database\Eloquent\Collection {#1147} "next" => array:2 [ "refs" => "1613343" "type" => "book_page" ] "previous" => array:2 [ "refs" => "1613341" "type" => "book_page" ] "tasks" => Illuminate\Database\Eloquent\Collection {#1237} ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } ] #original: array:24 [ "id" => 1612914 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "269" "field_page_end" => null "field_url" => "/8-klass/fizika/gromov-uchebnik/upr-47" "field_display_title" => "47" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1037} "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 {#1035} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1076} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1074} "content" => Illuminate\Database\Eloquent\Collection {#1077} "next" => array:2 [ "refs" => "1612915" "type" => "task" ] "previous" => array:2 [ "refs" => "1612913" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1129} "page" => array:2 [ "refs" => "1613342" "type" => "book_page" ] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] }
№47 (с. 269)
Условие. №47 (с. 269)
скриншот условия
47. Рассчитайте количество теплоты, которое выделяется или поглощается в процессах, перечисленных в задаче 39. Масса тела во всех случаях равна 2 кг.
Решение. №47 (с. 269)
Поскольку условие задачи 39 не предоставлено, произведем расчеты для нескольких типовых тепловых процессов. Для всех расчетов будем использовать справочные значения физических величин.
Дано:
Масса тела, $m = 2$ кг
Найти:
Количество теплоты $\text{Q}$ для каждого процесса.
Решение:
а) Нагревание стального бруска от 20 °С до 520 °С.
Количество теплоты, необходимое для нагревания тела (или выделяющееся при его охлаждении), рассчитывается по формуле:
$Q = c \cdot m \cdot (t_2 - t_1)$
где $\text{c}$ – удельная теплоемкость вещества, $\text{m}$ – масса тела, $t_1$ и $t_2$ – начальная и конечная температуры. Удельная теплоемкость стали $c_{стали} \approx 500 \frac{Дж}{кг \cdot °С}$.
В данном случае температура тела повышается, значит, теплота поглощается ($Q > 0$).
$Q_а = 500 \frac{Дж}{кг \cdot °С} \cdot 2 \, кг \cdot (520 \, °С - 20 \, °С) = 1000 \cdot 500 = 500000 \, Дж = 500 \, кДж$.
Ответ: поглощается 500 кДж теплоты.
б) Плавление льда при температуре 0 °С.
Количество теплоты, необходимое для плавления вещества, находящегося при температуре плавления, рассчитывается по формуле:
$Q = \lambda \cdot m$
где $\lambda$ – удельная теплота плавления. Удельная теплота плавления льда $\lambda_{льда} = 3.3 \cdot 10^5 \frac{Дж}{кг}$.
Плавление – это процесс, при котором теплота поглощается.
$Q_б = 3.3 \cdot 10^5 \frac{Дж}{кг} \cdot 2 \, кг = 6.6 \cdot 10^5 \, Дж = 660 \, кДж$.
Ответ: поглощается 660 кДж теплоты.
в) Парообразование воды при температуре 100 °С.
Количество теплоты, необходимое для превращения жидкости в пар при температуре кипения, рассчитывается по формуле:
$Q = L \cdot m$
где $\text{L}$ – удельная теплота парообразования. Удельная теплота парообразования воды $L_{воды} = 2.3 \cdot 10^6 \frac{Дж}{кг}$.
Парообразование – это процесс, при котором теплота поглощается.
$Q_в = 2.3 \cdot 10^6 \frac{Дж}{кг} \cdot 2 \, кг = 4.6 \cdot 10^6 \, Дж = 4.6 \, МДж$.
Ответ: поглощается 4.6 МДж теплоты.
г) Охлаждение кирпича от 100 °С до 20 °С.
Используем формулу для расчета количества теплоты при изменении температуры:
$Q = c \cdot m \cdot (t_2 - t_1)$
Удельная теплоемкость кирпича $c_{кирпича} \approx 880 \frac{Дж}{кг \cdot °С}$.
В данном случае температура тела понижается, значит, теплота выделяется ($Q < 0$).
$Q_г = 880 \frac{Дж}{кг \cdot °С} \cdot 2 \, кг \cdot (20 \, °С - 100 \, °С) = 1760 \cdot (-80) = -140800 \, Дж = -140.8 \, кДж$.
Знак "минус" указывает на то, что теплота выделяется.
Ответ: выделяется 140.8 кДж теплоты.
д) Кристаллизация свинца при температуре плавления (327 °С).
Количество теплоты, выделяющееся при кристаллизации (затвердевании) вещества, рассчитывается по формуле:
$Q = -\lambda \cdot m$
Удельная теплота плавления свинца $\lambda_{свинца} = 2.5 \cdot 10^4 \frac{Дж}{кг}$.
Кристаллизация – это процесс, при котором теплота выделяется.
$Q_д = -2.5 \cdot 10^4 \frac{Дж}{кг} \cdot 2 \, кг = -5 \cdot 10^4 \, Дж = -50 \, кДж$.
Ответ: выделяется 50 кДж теплоты.
Другие задания:
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