Q15 of 19 Page 374

A man whose mass is 50 kg moves up 15 steps each of height 15 cm in 45 seconds of time. Calculate the power used in climbing those stairs. (g = 10 m/s2)

Given

Mass of Body (m) = 50 Kg,


Time (t) = 45s,


Height of each step = 15 cm,


Acceleration due to gravity (g) = 10 m/s2.


Now


Weight = mg = 50×10 = 500N


Height of staircase =


(∵ 1 m = 100 cm)


Power =


⇒ Power =


Power = 25 Watt


Power used in climbing stairs = 25 W


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