Advertisements
Advertisements
प्रश्न
A man raises a box of mass 50 kg to a height of 2 m in 20s, while another man raises the same box to the same height in 50s. Calculated:
- the work done, and
- the power developed by each man. Take g = 10 N kg-1.
Advertisements
उत्तर
(i) Work done by each man = mgh
= 50 × 10 × 2
= 1000 J
(ii) Work done in first case = `w/t_1`
= `1000/20`
= 50 W
Work done in second case = `w/t_2`
= `1000/50`
= 20 W
APPEARS IN
संबंधित प्रश्न
A coolie X Carrying a load on his head climbs up a slope and another coolie Y carrying the identical load on his head move the same distance on a frictionless horizontal platform. Who does more work? Explain the reason.
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 force applied.
A body of mass m is moving with a uniform velocity u. A force is applied on the body due to which its velocity changes from u to v. How much work is being done by the force?
State the factors on which moment of force about a point depends.
What do you mean by a centrifugal force?
An engine does 54,000 J of work by exerting a force of 6000 N on it. What is the displacement in the direction of the force?
Work done by a force is equal to the product of ....... and ....
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.
For the following scenario, state whether the work done by gravity is positive, negative, or zero.
A person climbs a ladder.
For the following scenario, state whether the work done by gravity is positive, negative, or zero.
A car in neutral gear is coming down the slope.
