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प्रश्न
What is the work done by the gravitational force on the moon that revolves around the earth?
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उत्तर
The moon is revolving around the earth. In this process, the work done by the gravitational force is zero because the displacement of the moon is at the right angle to the gravitational force.
संबंधित प्रश्न
A boy weighing 40 kgf climbs up a stair of 30 steps each 20 cm high in 4 minutes and a girl weighing 30 kgf does the same in 3 minutes. Compare:
- The work done by them.
- The power developed by them.
Give the expression for mechanical advantage of an inclined plane in terms of the length of an inclined plane.
When a body moves in a circular path, how much work is done by the body? Give reason.
(Hint: The body is acted upon by the centripetal force.)
What physical quantity does the electron volt (eV) measure? How is it related to the S.I. unit of that quality?
What do you understand by the clockwise and anti clockwise moment of force?
State the condition when the work done by a force is negative. Explain with the help of examples.
A man spends 7.4 kJ energy in displacing a body by 74 m in the direction in which he applies force, in 2.5 s. Calculate the power spent (in H.P) by the man.
A boy takes 3 minutes to lift a 20 litre water bucket from a 20 m deep well, while his father does it in 2 minutes.
How much work each does? Take density of water = 103 kg m-3 and g = 9.8 N kg-1.
State the S.I. and C.G.S. units of energy. How are they related?
For the following scenario, state whether the work done by gravity is positive, negative, or zero.
A person climbs a ladder.
