Предмет: Физика, автор: chikasofya2008

с помощью рычага подняли груз массой 120 кг на высоту 16см.при этом совершили работу 750дж.определите КПД рычага
ПОМОГИТЕ ПОЖАЛУЙСТА

Ответы

Автор ответа: DeadCodeWriter
1

Ответ: КПД 25.6%

===================================================

m= 120 кг

h = 16см -> 0.16м

A=750Дж

n=?

n=Aпол/Азат->mgh/A->(120*10*0.16)/(750)*100=25.6%

==================================================

Предыдущий вопрос
Следующий вопрос
Похожие вопросы
Предмет: Окружающий мир, автор: sofaсофиья
приведите примеры цветочных культур урала
2 года назад
Предмет: Английский язык, автор: trofimtanua2001
ЗАДАНИЕ № 1 вариант 1
Текст задания:
Ответьте на предложенные вопросы тестового задания, выбрав правильный вариант(ы) ответа

I. Из четырех вариантов. (А), (В), (С), (D) выберите единственно правильный:
1. Shakespeare is__________ to understand than Agatha Christie.
(A) difficult (C) most difficult
(B) more difficult (D) the most difficult

2. I took a shower, shaved and__________ my best suit.
(A) wore (C) put on
(B) dressed (D) took off

3. The weather forecast said that _________ .
(A) it will rain in the afternoon (C) it rains in the afternoon
(B) it would rain in the afternoon (D) it will be raining in the afternoon

4. If you__________ to Paris you'll see the Eiffel Tower.
(A) go (C) went
(B) will go (D) would go

5. Who__________ America?
(A) discovered (C) did discovered
(B) did discover (D) discovers

6. When I___________ at Baker Street, Holmes was sitting by the fire deep in thought.
(A) reached
(B) entered
(C) arrived
(D) came

7. The most striking feature of the giraffe is its long neck, __________ has always been a source of curiosity.
(A) who (C) what
(B) whose (D) which

8. St Basil's Cathedral__________ in the mid-18th century in memory of the victory over Kazan.
(A) built (C) was builded
(B) was built (D) had been built

9. I usually go to school__________ foot.
(A) in (C) on
(B) with (D) by

10. __________ we had a lot of free time, we decided to go to the park.
(A) For
(B) Thus
(C)So
(D)As

11. I__________ English since December.
(A) will be learning
(B) am learning
(C) have been learning
(D) learn

12. Tell me__________ there is anything else you would like to see in London.
(A) that
(B)so
(C) which
(D)if

13. A secretary is a person who_________ letters.
(A) is typing
(B)types
(C)typed
(D) will type

14. Our planet is in grave danger__________ human activity.
(A) because
(B) the reason why
(C) for
(D) as a result of

15. My parents have__________ lived in London.
(A) always
(B) usually
(C) from time to time
(D) ever

16. It was___________ a boring film that I fell asleep in the middle of it.
(A) so
(B)such
(C) too
(D) very

17. We ate_________ cake. It was delicious.
(A) the all
(B) the whole
(C) the every bit
(D) each

18. If I were you, I_________ smoking.
(A) would give up
(B) gave up
(C) will give up
(D) give up

19. James said that he__________ a horse before.
(A) never rode
(B) has never ridden
(C) had never ridden
(D) would never ride

20. Neither Alex nor Nick_________ German.
(A) know
(B) are knowing
(C) don't know
(D) knows

21. She isn’t very popular. She has _________ friends.
(A) much
(B) many
(C) few
(D) little
2 года назад
Предмет: Русский язык, автор: варя255
замените словосочетание "визгливый крик" построенное на основе соглосования ,синоменичном словосочетание со связью управление ,помоги пожалуйста
2 года назад
Предмет: Українська мова, автор: wher194548
твір на тему "Символ Тварин"
8 лет назад
Предмет: Окружающий мир, автор: яяя2008
Рассмотри рисунки.Прочитай подписи.Составь рассказ о плоде какого нибудь растения. Плод вишни(костянка),Плод одуванчика(семянка),плод томата(ягода),плод гороха(боб),плод дуба(жёлудь).
8 лет назад