How is the power related to the speed at which a body can be lifted? How many kilograms will a man working at the power of 400 W, be able to lift at constant speed of 1 ms–1 vertically? (g = 10 ms–2)

Power = 400 W


Speed = 1m/s


g = 10 m/s2


Power = mgh/t = mgv


m = power/ g x speed = 400/ (10 x 1) = 40 Kg


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