Предмет: Физика, автор: EmilyTrick

Дрезина равномерно двигается по горизонтальным рельсам под действием силы тяги в 140 Н. Определите работу каждой силы, приложенных к ней на участке пути 1 км.

Ответы

Автор ответа: naf52NAF

При равномерном движении сила тяги равна силе трения.
Работа любой силы равна A=Fscosα
Работа силы тяжести, работа нормальной реакции опоры равна 0, т.к. cos90°=0
Работа силы тяги (cos 0°=1) равна: А=140 Н*1000 м*1=140000 Дж=140 кДж
Работа силы трения (cos 180°= -1) равна: А=140 Н*1000 м*(-1)= -140 кДж

Предыдущий вопрос

Следующий вопрос

Похожие вопросы

Предмет: Русский язык, автор: jopag97

Ко мне приходят новые идеи .Разбор по частям предложение(сказуемое ,подлежащее и т.д)

6 лет назад

Предмет: Английский язык, автор: kasianov05

Преобразуйте слова, чтобы они грамматически соответствовали содержанию текста.
A fearless Traveller
It’s hard to imagine anybody who looks less like an explorer that the Victorian traveler, Mary Kingsley. But she was one of the world’s ____________(1 tough) and _________________(2 adventurous) explorers. At a time when her friends _______________(3 to do) household chores and going to dances, Mary Kingsley ________________(4 to paddle up) rivers in a canoe, ______________(5 to eat) snakes and _______________(6 to poke) hippopotamuses with her umbrella in West Africa.
Kingsley was the daughter of a travelling doctor from London. She loved hearing her father’s travel stories, but there was no question that she would accompany ________(7 he) on ________(8 he) travels as her mother was frequently unwell and needed ________________(9 to care for). Suddenly, though, her life changed when both of her parents died within six weeks of one another. With no family __________________(10 responsibility), she decided to travel to West Africa, a place she ___________________(11 always, to dream of) visiting. She had two missions to complete while she ______________(12 to tour) the continent: one was to meet the native people of West Africa, learn about their customs and religions and write a book about the subject. The other was to collect tropical fish and reptiles for the British museum.
Her father’s medical friends had warned her about tropical diseases and other dangers of _________________(13 to travel) alone, but she ignored them and in 1893 she sailed to modern-day Sierra Leone on the ___________(14 one) of her two long journeys to West Africa.
She lived for a while with the local people, who taught her how to fish with pineapple _____________(15 leaf). After she _________________(16 to learn) the necessary skills, she _______________(17 to set off) alone along the river in search of fish and reptiles. During her travels, she became the first woman to climb the active volcano Mount Cameroon, and the first white person to paddle up the Ogowe River and to cross the jungle to the Remboue River.
On her travels, she had to deal with extreme heat, ___________(18 tornado) and various wild animals. Once, while she _____________(19 to canoe) along the Ogowe, she had an encounter with a crocodile. The crocodile was trying to climb into her canoe, so she _______________(20 to hit) it on the head with a paddle. Kingsley describes this and other similar encounters in her two books, Travels in West Africa and West African Studies, which she wrote when she returned from her travels. The books became bestsellers and _______________(21 to be) still in print today.
She collected eighteen species of reptile and sixty-five species of fish, two of which were previously unknown and _________________(22 to name) after her. However, that was not her only legacy: she also became well-known for her attitude towards the African people. She ____________(23 to be) the first explorer to show proper respect to the African people and their culture, and helped to change European attitudes towards ________________(24 they).

6 лет назад

Предмет: Информатика, автор: ssssmush

Укажите последовательность действий по отмене печати многостраничного документа

6 лет назад

Предмет: История, автор: magomegsultigov

что, на ваш взгляд, позволило Москве победить в борьбе за первенство с другими княжествами, претендвавшими на политическое лидерство на руси?

9 лет назад

Предмет: Математика, автор: Tanyadnep

Пачка мороженого стоит 4 грн. Сколько денег было у Ани, если она купила 5 пачек мороженого и у нее осталось 3 грн?

9 лет назад