В каком случае силой совершается отрицательная работа ?

В каком случае силой совершается отрицательная работа ?
- Предмет:
  Физика
- Автор:
  remington
- 5 лет назад

Ответы 1

Ответ:
Объяснение:При бросании мяча вверх сила тяжести направлена против движения, то есть препятствует ему. Следовательно, сила тяжести совершает отрицательную работу.При падении мяча направление силы тяжести и направление движения мяча совпадают, значит сила тяжести совершает положительную работу.
- Автор:
  juliana90
- 5 лет назад
- 0
Добавить свой ответ

Еще вопросы

Write a short email to a friend about what you
did last weekend. Use Ex. 2a as the model.
Напишите 8 предложений.Если надо имя то Влад.
- Предмет:
  Английский язык
- Автор:
  yaritzaclay
- 5 лет назад
- Ответов:
  
  5
- Смотреть
Помогите сделать пожалуйста! Допишите предложения как в примере:
He's only interested in tennis.
Tennis is his only interest.

1) She told us some good news.
The news .......
2) He needs more experience.
More experience .......
3) She looks very striking.
Her looks .......
4) They prefer to live on the outskirts.
The outskirts .......
5) Have you seen the scissors?
Do you know we're .......
- Предмет:
  Английский язык
- Автор:
  cynthianpm6
- 5 лет назад
- Ответов:
  
  2
- Смотреть
Cоотнести текст с тем о чем он
1.“ Environmental racism is inequitable
distribution of environmental hazards basedon race. The Federal Agency for Toxic Substances and Disease Registry considerslead poisoning to be the number one environmental health problem for children inthe United States. Some 4 million children many of whom are African American,Latino and Native American- have dangerously high lead levels in their bodies. Thislead is absorbed from contaminated drinking water and soil polluted by industrial effluents and automobile exhaust.”

2.“Every year humans kill about 100 million sharks, skates and rays, about half of
them caught as unwanted “by catch” while fishing for other species. Sharks are
particularly sensitive to overfishing because they grow slowly, mature late and havefew young each generation. As top predators, sharks play a crucial role in the healthof the ocean ecosystems and their extermination could lead to major ecological
changes in the ocean”.

3.“ Every second, on average, four or five children are born somewhere on the earth.I that same second, two other people die. This difference between births anddeaths means a net gain of roughly 2.5 more humans per second in the worldpopulation. This means we are adding 9,000 per hour, 217,000 per day, or about 79
million more people per year.”

4.“ World wide, we lost between 9 million and 12 million ha of forest per year from1990 to 2000. Clear-cutting and burning especially in order to get pasture and
cropland have turned many forests into a dry, barren ground”.

5.“ In February 2002, a huge section of the Larsen B Ice Shelf along The AntarcticPeninsula coast suddenly disintegrated into thousands of icebergs. The total volumeof ice released was the equivalent to 29 trillion bags of party ice. Climatologistswarn that this dramatic collapse could be a signal of global climate change and an omen of catastrophic events to come.”

6.“ How does the air taste, feel, smell, and look in your neighbourhood? Chances are
that wherever you live, the air is contaminated to some degree. Smoke, dust,corrosive gases andtoxic compounds are present nearly everywhere.”

7.“ A 1 percent loss of ozone results in a 2 percent increase in UV rays reaching theearth’s surface and could result in about a million extra human skin cancers peryear worldwide.”

8.“ Sulfur dioxide and sulphuric acid released by industry causes massive destructionof the vegetation. Rains then wash away the exposed soil, leaving a barren
moonscape.”

9.“Pollution from factory pipes has been vastly reduced but erosion from farm fields,
construction sites, airborne mercury, sulphur and other substances are increasingly
contaminating lakes and wetlands.”
A Animalextinction
B Acid rain
C Air pollution
D Overpopulation
F Water pollution
K Deforestation
I Ozone Depletion
V Global warming
L Hazardouswaste
- Предмет:
  Английский язык
- Автор:
  snowflake
- 5 лет назад
- Ответов:
  
  1
- Смотреть
Что означает роза в гербе
- Предмет:
  Обществознание
- Автор:
  leandronohb
- 5 лет назад
- Ответов:
  
  3
- Смотреть

В каком случае силой совершается отрицательная работа ?

Ответы 1

Топ пользователей