Q35 of 146 Page 163

A boy weighing 40 kg carriers a box weighing 20 kg to the top of a building 15 m high in 25 seconds. Calculate the power. (g = 10 m/s2)

Given,

Mass of boy = 40Kg


Mass of box = 20 kg


Total mass = 40 + 20 = 60kg


g = 10m/s2


h = 15m


t = 25 sec


Power = mgh/t


=60 × 10 × 15/ 25


= 360 W


Power = 360 W


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Define power. Give the SI unit of power.

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Which one of the following is not the unit of energy?

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