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प्रश्न
Work done by a boy depends on the time in which he does work.
विकल्प
True
False
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उत्तर
False.
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संबंधित प्रश्न
Define 1 J of work.
Give reasons for the following. No work is done if a man is pushing against a wall.
A boy throws a rubber ball vertically upwards. What type of work, positive or negative, is done : by the force applied by the boy?
(a) by the force applied by the boy?
(b) by the gravitational force of earth?
Write the formula for work done on a body when the body moves at an angle to the direction of force. Give the meaning of each symbol used.
Name the physical quantity whose SI unit is Nm.
A uniform circular motion is an accelerated motion. Justify it.
An electric motor drives a machine which lifts a mass of 4 kg through a height of 10 m in 5 s at a constant speed. Assuming g = 10 ms-2, calculate
(i) the amount of work done, (ii) the power of the machine.
A water pump raises 50 kg of water through a height of 25 m in 5s. Calculate the power supplied by the pump (Take: g = 10 N kg−1).
