Номер 4, страница 71 - гдз по физике 9 класс учебник Изергин

Физика, 9 класс Учебник, автор: Изергин Эдуард Тимофеевич, издательство Русское слово, Москва, 2019

Авторы: Изергин Э. Т.

Тип: Учебник

Серия: инновационная школа

Издательство: Русское слово

Год издания: 2019 - 2026

Цвет обложки: синий

ISBN: 978-5-533-01069-6

Глава III. Механические колебания и волны. Параграф 14. Равномерное движение по окружности - номер 4, страница 71.

App\Models\Task {#1024 // resources/views/models/task/default.blade.php
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            "text" => "<p><strong>4.</strong> Для каждого из наблюдаемых явлений, описанных в начале параграфа, укажите, если это возможно, период, частоту, угловую и линейную скорости.</p>"
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            "task" => array:2 [
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            "text" => "<p><strong>4.</strong> Для каждого из наблюдаемых явлений, описанных в начале параграфа, укажите, если это возможно, период, частоту, угловую и линейную скорости.</p>"
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            "edition" => Illuminate\Database\Eloquent\Collection {#1113
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                0 => App\Models\Edition {#1114
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            "task" => array:2 [
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            "text" => "<p>Поскольку в задании не указаны конкретные явления, описанные в начале параграфа, рассмотрим несколько стандартных примеров периодических движений.</p><p><strong>Вращение Земли вокруг своей оси</strong></p><p>Это периодическое движение.<br><em>Период (T)</em> - время одного полного оборота. Для Земли это звёздные сутки. $T \approx 23 \text{ ч } 56 \text{ мин } 4 \text{ с} = 86164 \text{ с}$. Часто для упрощения принимают $T = 24 \text{ ч} = 86400 \text{ с}$.<br><em>Частота (ν)</em> - число оборотов в единицу времени. Она связана с периодом соотношением $\nu = 1/T$. Для Земли $\nu = 1 / 86164 \text{ с} \approx 1.16 \times 10^{-5} \text{ Гц}$.<br><em>Угловая скорость (ω)</em> - скорость изменения угла поворота. Она связана с периодом как $\omega = 2\pi/T$. Для Земли $\omega = 2\pi / 86164 \text{ с} \approx 7.29 \times 10^{-5} \text{ рад/с}$. Эта величина одинакова для всех точек на Земле (кроме точек на оси вращения).<br><em>Линейная скорость (v)</em> - скорость движения точки. Она зависит от расстояния до оси вращения $\text{R}$ по формуле $v = \omega R$. Для точки на поверхности Земли на географической широте $\phi$, расстояние до оси вращения равно $R = R_З \cos(\phi)$, где $R_З$ - радиус Земли. Таким образом, линейная скорость на экваторе ($\phi = 0^{\circ}$, $R \approx 6378$ км) максимальна и составляет $v \approx 465 \text{ м/с}$, а на полюсах ($\phi = 90^{\circ}$, $R = 0$) равна нулю. Указать единое значение линейной скорости для всего явления невозможно.</p><p><strong>Ответ:</strong> Период $T \approx 86164 \text{ с}$, частота $\nu \approx 1.16 \times 10^{-5} \text{ Гц}$, угловая скорость $\omega \approx 7.29 \times 10^{-5} \text{ рад/с}$. Линейная скорость $\text{v}$ зависит от широты и изменяется от $\text{0}$ на полюсах до примерно $465 \text{ м/с}$ на экваторе.</p><p><strong>Обращение Земли вокруг Солнца</strong></p><p>Это периодическое движение.<br><em>Период (T)</em> - время одного полного оборота вокруг Солнца, что составляет один год. $T \approx 365.25 \text{ суток} \approx 3.156 \times 10^7 \text{ с}$.<br><em>Частота (ν)</em> - $\nu = 1/T = 1 / (3.156 \times 10^7 \text{ с}) \approx 3.17 \times 10^{-8} \text{ Гц}$.<br><em>Угловая скорость (ω)</em> - Поскольку орбита Земли — эллипс, угловая скорость не является постоянной. Однако можно рассчитать среднюю угловую скорость: $\omega_{ср} = 2\pi/T = 2\pi / (3.156 \times 10^7 \text{ с}) \approx 1.99 \times 10^{-7} \text{ рад/с}$.<br><em>Линейная скорость (v)</em> - также не является постоянной из-за эллиптической орбиты (согласно второму закону Кеплера). Она максимальна в перигелии и минимальна в афелии. Средняя линейная скорость может быть найдена как $v_{ср} = \omega_{ср} R_{ср}$, где $R_{ср}$ - средний радиус орбиты (около $1.496 \times 10^{11} \text{ м}$). $v_{ср} \approx (1.99 \times 10^{-7} \text{ рад/с}) \times (1.496 \times 10^{11} \text{ м}) \approx 29.8 \text{ км/с}$.</p><p><strong>Ответ:</strong> Период $T \approx 3.156 \times 10^7 \text{ с}$, частота $\nu \approx 3.17 \times 10^{-8} \text{ Гц}$. Средняя угловая скорость $\omega_{ср} \approx 1.99 \times 10^{-7} \text{ рад/с}$, средняя линейная скорость $v_{ср} \approx 29.8 \text{ км/с}$. Мгновенные значения угловой и линейной скоростей непостоянны.</p><p><strong>Движение секундной стрелки часов</strong></p><p>Это пример равномерного вращательного движения.<br><em>Период (T)</em> - время одного полного оборота. $T = 60 \text{ с}$.<br><em>Частота (ν)</em> - $\nu = 1/T = 1/60 \text{ Гц}$.<br><em>Угловая скорость (ω)</em> - постоянна для всех точек стрелки. $\omega = 2\pi/T = 2\pi/60 = \pi/30 \text{ рад/с} \approx 0.105 \text{ рад/с}$.<br><em>Линейная скорость (v)</em> - зависит от расстояния $\text{r}$ от центра вращения: $v = \omega r = (\pi/30)r$. Линейная скорость равна нулю в точке крепления стрелки и максимальна на её конце. Поэтому указать единое значение для всей стрелки невозможно.</p><p><strong>Ответ:</strong> Период $T = 60 \text{ с}$, частота $\nu = 1/60 \text{ Гц}$, угловая скорость $\omega = \pi/30 \text{ рад/с}$. Линейная скорость $\text{v}$ пропорциональна расстоянию от центра вращения ($v = (\pi/30)r$).</p><p><strong>Движение минутной стрелки часов</strong></p><p>Это пример равномерного вращательного движения.<br><em>Период (T)</em> - время одного полного оборота. $T = 60 \text{ мин} = 3600 \text{ с}$.<br><em>Частота (ν)</em> - $\nu = 1/T = 1/3600 \text{ Гц}$.<br><em>Угловая скорость (ω)</em> - постоянна для всех точек стрелки. $\omega = 2\pi/T = 2\pi/3600 = \pi/1800 \text{ рад/с}$.<br><em>Линейная скорость (v)</em> - зависит от расстояния $\text{r}$ от центра вращения: $v = \omega r = (\pi/1800)r$. Линейная скорость равна нулю в точке крепления стрелки и максимальна на её конце.</p><p><strong>Ответ:</strong> Период $T = 3600 \text{ с}$, частота $\nu = 1/3600 \text{ Гц}$, угловая скорость $\omega = \pi/1800 \text{ рад/с}$. Линейная скорость $\text{v}$ пропорциональна расстоянию от центра вращения ($v = (\pi/1800)r$).</p><p><strong>Движение часовой стрелки часов</strong></p><p>Это пример равномерного вращательного движения.<br><em>Период (T)</em> - время одного полного оборота (на стандартном циферблате). $T = 12 \text{ ч} = 12 \times 3600 \text{ с} = 43200 \text{ с}$.<br><em>Частота (ν)</em> - $\nu = 1/T = 1/43200 \text{ Гц}$.<br><em>Угловая скорость (ω)</em> - постоянна для всех точек стрелки. $\omega = 2\pi/T = 2\pi/43200 = \pi/21600 \text{ рад/с}$.<br><em>Линейная скорость (v)</em> - зависит от расстояния $\text{r}$ от центра вращения: $v = \omega r = (\pi/21600)r$. Линейная скорость равна нулю в точке крепления стрелки и максимальна на её конце.</p><p><strong>Ответ:</strong> Период $T = 43200 \text{ с}$, частота $\nu = 1/43200 \text{ Гц}$, угловая скорость $\omega = \pi/21600 \text{ рад/с}$. Линейная скорость $\text{v}$ пропорциональна расстоянию от центра вращения ($v = (\pi/21600)r$).</p>"
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            "text" => "<p>Поскольку в задании не указаны конкретные явления, описанные в начале параграфа, рассмотрим несколько стандартных примеров периодических движений.</p><p><strong>Вращение Земли вокруг своей оси</strong></p><p>Это периодическое движение.<br><em>Период (T)</em> - время одного полного оборота. Для Земли это звёздные сутки. $T \approx 23 \text{ ч } 56 \text{ мин } 4 \text{ с} = 86164 \text{ с}$. Часто для упрощения принимают $T = 24 \text{ ч} = 86400 \text{ с}$.<br><em>Частота (ν)</em> - число оборотов в единицу времени. Она связана с периодом соотношением $\nu = 1/T$. Для Земли $\nu = 1 / 86164 \text{ с} \approx 1.16 \times 10^{-5} \text{ Гц}$.<br><em>Угловая скорость (ω)</em> - скорость изменения угла поворота. Она связана с периодом как $\omega = 2\pi/T$. Для Земли $\omega = 2\pi / 86164 \text{ с} \approx 7.29 \times 10^{-5} \text{ рад/с}$. Эта величина одинакова для всех точек на Земле (кроме точек на оси вращения).<br><em>Линейная скорость (v)</em> - скорость движения точки. Она зависит от расстояния до оси вращения $\text{R}$ по формуле $v = \omega R$. Для точки на поверхности Земли на географической широте $\phi$, расстояние до оси вращения равно $R = R_З \cos(\phi)$, где $R_З$ - радиус Земли. Таким образом, линейная скорость на экваторе ($\phi = 0^{\circ}$, $R \approx 6378$ км) максимальна и составляет $v \approx 465 \text{ м/с}$, а на полюсах ($\phi = 90^{\circ}$, $R = 0$) равна нулю. Указать единое значение линейной скорости для всего явления невозможно.</p><p><strong>Ответ:</strong> Период $T \approx 86164 \text{ с}$, частота $\nu \approx 1.16 \times 10^{-5} \text{ Гц}$, угловая скорость $\omega \approx 7.29 \times 10^{-5} \text{ рад/с}$. Линейная скорость $\text{v}$ зависит от широты и изменяется от $\text{0}$ на полюсах до примерно $465 \text{ м/с}$ на экваторе.</p><p><strong>Обращение Земли вокруг Солнца</strong></p><p>Это периодическое движение.<br><em>Период (T)</em> - время одного полного оборота вокруг Солнца, что составляет один год. $T \approx 365.25 \text{ суток} \approx 3.156 \times 10^7 \text{ с}$.<br><em>Частота (ν)</em> - $\nu = 1/T = 1 / (3.156 \times 10^7 \text{ с}) \approx 3.17 \times 10^{-8} \text{ Гц}$.<br><em>Угловая скорость (ω)</em> - Поскольку орбита Земли — эллипс, угловая скорость не является постоянной. Однако можно рассчитать среднюю угловую скорость: $\omega_{ср} = 2\pi/T = 2\pi / (3.156 \times 10^7 \text{ с}) \approx 1.99 \times 10^{-7} \text{ рад/с}$.<br><em>Линейная скорость (v)</em> - также не является постоянной из-за эллиптической орбиты (согласно второму закону Кеплера). Она максимальна в перигелии и минимальна в афелии. Средняя линейная скорость может быть найдена как $v_{ср} = \omega_{ср} R_{ср}$, где $R_{ср}$ - средний радиус орбиты (около $1.496 \times 10^{11} \text{ м}$). $v_{ср} \approx (1.99 \times 10^{-7} \text{ рад/с}) \times (1.496 \times 10^{11} \text{ м}) \approx 29.8 \text{ км/с}$.</p><p><strong>Ответ:</strong> Период $T \approx 3.156 \times 10^7 \text{ с}$, частота $\nu \approx 3.17 \times 10^{-8} \text{ Гц}$. Средняя угловая скорость $\omega_{ср} \approx 1.99 \times 10^{-7} \text{ рад/с}$, средняя линейная скорость $v_{ср} \approx 29.8 \text{ км/с}$. Мгновенные значения угловой и линейной скоростей непостоянны.</p><p><strong>Движение секундной стрелки часов</strong></p><p>Это пример равномерного вращательного движения.<br><em>Период (T)</em> - время одного полного оборота. $T = 60 \text{ с}$.<br><em>Частота (ν)</em> - $\nu = 1/T = 1/60 \text{ Гц}$.<br><em>Угловая скорость (ω)</em> - постоянна для всех точек стрелки. $\omega = 2\pi/T = 2\pi/60 = \pi/30 \text{ рад/с} \approx 0.105 \text{ рад/с}$.<br><em>Линейная скорость (v)</em> - зависит от расстояния $\text{r}$ от центра вращения: $v = \omega r = (\pi/30)r$. Линейная скорость равна нулю в точке крепления стрелки и максимальна на её конце. Поэтому указать единое значение для всей стрелки невозможно.</p><p><strong>Ответ:</strong> Период $T = 60 \text{ с}$, частота $\nu = 1/60 \text{ Гц}$, угловая скорость $\omega = \pi/30 \text{ рад/с}$. Линейная скорость $\text{v}$ пропорциональна расстоянию от центра вращения ($v = (\pi/30)r$).</p><p><strong>Движение минутной стрелки часов</strong></p><p>Это пример равномерного вращательного движения.<br><em>Период (T)</em> - время одного полного оборота. $T = 60 \text{ мин} = 3600 \text{ с}$.<br><em>Частота (ν)</em> - $\nu = 1/T = 1/3600 \text{ Гц}$.<br><em>Угловая скорость (ω)</em> - постоянна для всех точек стрелки. $\omega = 2\pi/T = 2\pi/3600 = \pi/1800 \text{ рад/с}$.<br><em>Линейная скорость (v)</em> - зависит от расстояния $\text{r}$ от центра вращения: $v = \omega r = (\pi/1800)r$. Линейная скорость равна нулю в точке крепления стрелки и максимальна на её конце.</p><p><strong>Ответ:</strong> Период $T = 3600 \text{ с}$, частота $\nu = 1/3600 \text{ Гц}$, угловая скорость $\omega = \pi/1800 \text{ рад/с}$. Линейная скорость $\text{v}$ пропорциональна расстоянию от центра вращения ($v = (\pi/1800)r$).</p><p><strong>Движение часовой стрелки часов</strong></p><p>Это пример равномерного вращательного движения.<br><em>Период (T)</em> - время одного полного оборота (на стандартном циферблате). $T = 12 \text{ ч} = 12 \times 3600 \text{ с} = 43200 \text{ с}$.<br><em>Частота (ν)</em> - $\nu = 1/T = 1/43200 \text{ Гц}$.<br><em>Угловая скорость (ω)</em> - постоянна для всех точек стрелки. $\omega = 2\pi/T = 2\pi/43200 = \pi/21600 \text{ рад/с}$.<br><em>Линейная скорость (v)</em> - зависит от расстояния $\text{r}$ от центра вращения: $v = \omega r = (\pi/21600)r$. Линейная скорость равна нулю в точке крепления стрелки и максимальна на её конце.</p><p><strong>Ответ:</strong> Период $T = 43200 \text{ с}$, частота $\nu = 1/43200 \text{ Гц}$, угловая скорость $\omega = \pi/21600 \text{ рад/с}$. Линейная скорость $\text{v}$ пропорциональна расстоянию от центра вращения ($v = (\pi/21600)r$).</p>"
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            "tasks" => Illuminate\Database\Eloquent\Collection {#1197
              #items: array:7 [
                0 => App\Models\Task {#1198
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
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                  #perPage: 15
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                    "created_at" => "2026-04-10 13:58:26"
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                    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1199 …2}
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                    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1237 …2}
                    "content" => Illuminate\Database\Eloquent\Collection {#1311 …2}
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                    "book" => Illuminate\Database\Eloquent\Collection {#1322 …2}
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                    0 => "*"
                  ]
                }
                1 => App\Models\Task {#1323
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
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                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [
                    "id" => 1439729
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
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                    "field_url" => "/9-klass/fizika/izergin-uchebnik/14-2"
                    "field_display_title" => "2"
                    "field_outside_task" => null
                    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1324 …2}
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                    "edition_groups" => Illuminate\Database\Eloquent\Collection {#1325 …2}
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                    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1327 …2}
                    "content" => Illuminate\Database\Eloquent\Collection {#1328 …2}
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                    "previous" => array:2 [ …2]
                    "book" => Illuminate\Database\Eloquent\Collection {#1333 …2}
                    "page" => array:2 [ …2]
                  ]
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                    0 => "*"
                  ]
                }
                2 => 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" => 1439730
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
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                    "field_url" => "/9-klass/fizika/izergin-uchebnik/14-3"
                    "field_display_title" => "3"
                    "field_outside_task" => null
                    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1335 …2}
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                    "edition_groups" => Illuminate\Database\Eloquent\Collection {#1336 …2}
                    "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1337 …2}
                    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1338 …2}
                    "content" => Illuminate\Database\Eloquent\Collection {#1339 …2}
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                    "book" => Illuminate\Database\Eloquent\Collection {#1356 …2}
                    "page" => array:2 [ …2]
                  ]
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                    "id" => 1439730
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                    "field_outside_task" => null
                    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1335 …2}
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                    0 => "*"
                  ]
                }
                3 => App\Models\Task {#1357
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
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                  #escapeWhenCastingToString: false
                  #attributes: array:24 [
                    "id" => 1439731
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
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                    "field_url" => "/9-klass/fizika/izergin-uchebnik/14-4"
                    "field_display_title" => "4"
                    "field_outside_task" => null
                    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1358 …2}
                    "field_metatags_title" => null
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                    "field_h1" => null
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                    "edition_groups" => Illuminate\Database\Eloquent\Collection {#1359 …2}
                    "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1360 …2}
                    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1361 …2}
                    "content" => Illuminate\Database\Eloquent\Collection {#1362 …2}
                    "next" => array:2 [ …2]
                    "previous" => array:2 [ …2]
                    "book" => Illuminate\Database\Eloquent\Collection {#1379 …2}
                    "page" => array:2 [ …2]
                  ]
                  #original: array:24 [
                    "id" => 1439731
                    "created_at" => "2026-04-10 13:58:26"
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                    "field_page_start" => "71"
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                    "field_display_title" => "4"
                    "field_outside_task" => null
                    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1358 …2}
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                    "edition_groups" => Illuminate\Database\Eloquent\Collection {#1359 …2}
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                    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1361 …2}
                    "content" => Illuminate\Database\Eloquent\Collection {#1362 …2}
                    "next" => array:2 [ …2]
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                    "book" => Illuminate\Database\Eloquent\Collection {#1379 …2}
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                  #visible: []
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                    0 => "*"
                  ]
                }
                4 => App\Models\Task {#1380
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
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                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [
                    "id" => 1439732
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_page_start" => "71"
                    "field_page_end" => null
                    "field_url" => "/9-klass/fizika/izergin-uchebnik/14-5"
                    "field_display_title" => "5"
                    "field_outside_task" => null
                    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1381 …2}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
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                    "breadcrumbs" => []
                    "edition_groups" => Illuminate\Database\Eloquent\Collection {#1382 …2}
                    "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1383 …2}
                    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1384 …2}
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                    "book" => Illuminate\Database\Eloquent\Collection {#1402 …2}
                    "page" => array:2 [ …2]
                  ]
                  #original: array:24 [
                    "id" => 1439732
                    "created_at" => "2026-04-10 13:58:26"
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                    "field_display_title" => "5"
                    "field_outside_task" => null
                    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1381 …2}
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                    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1384 …2}
                    "content" => Illuminate\Database\Eloquent\Collection {#1385 …2}
                    "next" => array:2 [ …2]
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                    "book" => Illuminate\Database\Eloquent\Collection {#1402 …2}
                    "page" => array:2 [ …2]
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                  #hidden: []
                  #visible: []
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                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
                5 => App\Models\Task {#1403
                  #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" => 1439733
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_page_start" => "71"
                    "field_page_end" => null
                    "field_url" => "/9-klass/fizika/izergin-uchebnik/14-6"
                    "field_display_title" => "6"
                    "field_outside_task" => null
                    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1404 …2}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
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                    "breadcrumbs" => []
                    "edition_groups" => Illuminate\Database\Eloquent\Collection {#1405 …2}
                    "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1406 …2}
                    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1407 …2}
                    "content" => Illuminate\Database\Eloquent\Collection {#1408 …2}
                    "next" => array:2 [ …2]
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                    "book" => Illuminate\Database\Eloquent\Collection {#1425 …2}
                    "page" => array:2 [ …2]
                  ]
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                    "id" => 1439733
                    "created_at" => "2026-04-10 13:58:26"
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                    "field_url" => "/9-klass/fizika/izergin-uchebnik/14-6"
                    "field_display_title" => "6"
                    "field_outside_task" => null
                    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1404 …2}
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                    0 => "*"
                  ]
                }
                6 => App\Models\Task {#1426
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
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                  #perPage: 15
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                  #attributes: array:24 [
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                    "created_at" => "2026-04-10 13:58:26"
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                    "field_url" => "/9-klass/fizika/izergin-uchebnik/14-7"
                    "field_display_title" => "7"
                    "field_outside_task" => null
                    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1427 …2}
                    "field_metatags_title" => null
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                    "edition_groups" => Illuminate\Database\Eloquent\Collection {#1428 …2}
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                    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1430 …2}
                    "content" => Illuminate\Database\Eloquent\Collection {#1431 …2}
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                  #original: array:24 [
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                    "field_display_title" => "7"
                    "field_outside_task" => null
                    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1427 …2}
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                    0 => "*"
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                }
              ]
              #escapeWhenCastingToString: false
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          ]
          #original: array:21 [
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            "field_display_title" => "71"
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            "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1157}
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№4 (с. 71)
Условие. №4 (с. 71)
скриншот условия
Физика, 9 класс Учебник, автор: Изергин Эдуард Тимофеевич, издательство Русское слово, Москва, 2019, страница 71, номер 4, Условие

4. Для каждого из наблюдаемых явлений, описанных в начале параграфа, укажите, если это возможно, период, частоту, угловую и линейную скорости.

Решение. №4 (с. 71)

Поскольку в задании не указаны конкретные явления, описанные в начале параграфа, рассмотрим несколько стандартных примеров периодических движений.

Вращение Земли вокруг своей оси

Это периодическое движение.
Период (T) - время одного полного оборота. Для Земли это звёздные сутки. $T \approx 23 \text{ ч } 56 \text{ мин } 4 \text{ с} = 86164 \text{ с}$. Часто для упрощения принимают $T = 24 \text{ ч} = 86400 \text{ с}$.
Частота (ν) - число оборотов в единицу времени. Она связана с периодом соотношением $\nu = 1/T$. Для Земли $\nu = 1 / 86164 \text{ с} \approx 1.16 \times 10^{-5} \text{ Гц}$.
Угловая скорость (ω) - скорость изменения угла поворота. Она связана с периодом как $\omega = 2\pi/T$. Для Земли $\omega = 2\pi / 86164 \text{ с} \approx 7.29 \times 10^{-5} \text{ рад/с}$. Эта величина одинакова для всех точек на Земле (кроме точек на оси вращения).
Линейная скорость (v) - скорость движения точки. Она зависит от расстояния до оси вращения $\text{R}$ по формуле $v = \omega R$. Для точки на поверхности Земли на географической широте $\phi$, расстояние до оси вращения равно $R = R_З \cos(\phi)$, где $R_З$ - радиус Земли. Таким образом, линейная скорость на экваторе ($\phi = 0^{\circ}$, $R \approx 6378$ км) максимальна и составляет $v \approx 465 \text{ м/с}$, а на полюсах ($\phi = 90^{\circ}$, $R = 0$) равна нулю. Указать единое значение линейной скорости для всего явления невозможно.

Ответ: Период $T \approx 86164 \text{ с}$, частота $\nu \approx 1.16 \times 10^{-5} \text{ Гц}$, угловая скорость $\omega \approx 7.29 \times 10^{-5} \text{ рад/с}$. Линейная скорость $\text{v}$ зависит от широты и изменяется от $\text{0}$ на полюсах до примерно $465 \text{ м/с}$ на экваторе.

Обращение Земли вокруг Солнца

Это периодическое движение.
Период (T) - время одного полного оборота вокруг Солнца, что составляет один год. $T \approx 365.25 \text{ суток} \approx 3.156 \times 10^7 \text{ с}$.
Частота (ν) - $\nu = 1/T = 1 / (3.156 \times 10^7 \text{ с}) \approx 3.17 \times 10^{-8} \text{ Гц}$.
Угловая скорость (ω) - Поскольку орбита Земли — эллипс, угловая скорость не является постоянной. Однако можно рассчитать среднюю угловую скорость: $\omega_{ср} = 2\pi/T = 2\pi / (3.156 \times 10^7 \text{ с}) \approx 1.99 \times 10^{-7} \text{ рад/с}$.
Линейная скорость (v) - также не является постоянной из-за эллиптической орбиты (согласно второму закону Кеплера). Она максимальна в перигелии и минимальна в афелии. Средняя линейная скорость может быть найдена как $v_{ср} = \omega_{ср} R_{ср}$, где $R_{ср}$ - средний радиус орбиты (около $1.496 \times 10^{11} \text{ м}$). $v_{ср} \approx (1.99 \times 10^{-7} \text{ рад/с}) \times (1.496 \times 10^{11} \text{ м}) \approx 29.8 \text{ км/с}$.

Ответ: Период $T \approx 3.156 \times 10^7 \text{ с}$, частота $\nu \approx 3.17 \times 10^{-8} \text{ Гц}$. Средняя угловая скорость $\omega_{ср} \approx 1.99 \times 10^{-7} \text{ рад/с}$, средняя линейная скорость $v_{ср} \approx 29.8 \text{ км/с}$. Мгновенные значения угловой и линейной скоростей непостоянны.

Движение секундной стрелки часов

Это пример равномерного вращательного движения.
Период (T) - время одного полного оборота. $T = 60 \text{ с}$.
Частота (ν) - $\nu = 1/T = 1/60 \text{ Гц}$.
Угловая скорость (ω) - постоянна для всех точек стрелки. $\omega = 2\pi/T = 2\pi/60 = \pi/30 \text{ рад/с} \approx 0.105 \text{ рад/с}$.
Линейная скорость (v) - зависит от расстояния $\text{r}$ от центра вращения: $v = \omega r = (\pi/30)r$. Линейная скорость равна нулю в точке крепления стрелки и максимальна на её конце. Поэтому указать единое значение для всей стрелки невозможно.

Ответ: Период $T = 60 \text{ с}$, частота $\nu = 1/60 \text{ Гц}$, угловая скорость $\omega = \pi/30 \text{ рад/с}$. Линейная скорость $\text{v}$ пропорциональна расстоянию от центра вращения ($v = (\pi/30)r$).

Движение минутной стрелки часов

Это пример равномерного вращательного движения.
Период (T) - время одного полного оборота. $T = 60 \text{ мин} = 3600 \text{ с}$.
Частота (ν) - $\nu = 1/T = 1/3600 \text{ Гц}$.
Угловая скорость (ω) - постоянна для всех точек стрелки. $\omega = 2\pi/T = 2\pi/3600 = \pi/1800 \text{ рад/с}$.
Линейная скорость (v) - зависит от расстояния $\text{r}$ от центра вращения: $v = \omega r = (\pi/1800)r$. Линейная скорость равна нулю в точке крепления стрелки и максимальна на её конце.

Ответ: Период $T = 3600 \text{ с}$, частота $\nu = 1/3600 \text{ Гц}$, угловая скорость $\omega = \pi/1800 \text{ рад/с}$. Линейная скорость $\text{v}$ пропорциональна расстоянию от центра вращения ($v = (\pi/1800)r$).

Движение часовой стрелки часов

Это пример равномерного вращательного движения.
Период (T) - время одного полного оборота (на стандартном циферблате). $T = 12 \text{ ч} = 12 \times 3600 \text{ с} = 43200 \text{ с}$.
Частота (ν) - $\nu = 1/T = 1/43200 \text{ Гц}$.
Угловая скорость (ω) - постоянна для всех точек стрелки. $\omega = 2\pi/T = 2\pi/43200 = \pi/21600 \text{ рад/с}$.
Линейная скорость (v) - зависит от расстояния $\text{r}$ от центра вращения: $v = \omega r = (\pi/21600)r$. Линейная скорость равна нулю в точке крепления стрелки и максимальна на её конце.

Ответ: Период $T = 43200 \text{ с}$, частота $\nu = 1/43200 \text{ Гц}$, угловая скорость $\omega = \pi/21600 \text{ рад/с}$. Линейная скорость $\text{v}$ пропорциональна расстоянию от центра вращения ($v = (\pi/21600)r$).

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