Advertisements
Advertisements
प्रश्न
For the following scenario, state whether the work done by gravity is positive, negative, or zero.
A person walks on a levelled road.
Advertisements
उत्तर
Zero work is done.
Explanation:
When a person walks on a levelled, no work is done against the force of gravity, as the displacement of the person is normal to the direction of the force of gravity, which is vertically downwards.
संबंधित प्रश्न
State the condition when the work done by a force is positive. Explain with the help of examples.
What are the S.I. and C.G.S units of work? How are they related? Establish the relationship.
What is a centripetal force?
What do you mean by a centrifugal force?
How much force is applied on a body when 150 J of work is done in displacing the body through a distance of 10 m in the direction of the force?
It takes 20 s for a person A of mass 50 kg to climb up the stairs, while another person B of same mass does the same in 15 s. Compare the power developed by the persons A and B.
What is the S.I. unit of work? Define it.
The world record for weight lifting was held by Sergei Didyk of the USSR. He lifted 261 kg to a height of 2.3 m in 4s; find:
(a) Weight lifted by him
(b) Work done by him
(c) Power developed by him. (g = 10m/s2)
For the following scenario, state whether the work done by gravity is positive, negative, or zero.
A person climbs a ladder.
A boy weighing 50 kgf climbs up from the first floor at a height of 3 m above the ground to the third floor at a height of 9 m above the ground. What will be the increase in his gravitational potential energy? (Take g = 10 N kg-1).
