A man of mass 60 kg runs up a flight of 60 steps in 40 seconds.If each step is 20 cm high,his power is

Question

Quizplus · Accepted Answer

To calculate power, we need to find the work done by the man and divide it by the time taken.

Work done = Force x distance
Force = mass x acceleration

The man is running against gravity, so the force needed to lift his body is equal to his weight.

Force = weight = mass x gravitational acceleration = 60 kg x 9.8 m/s^2 = 588 N

The distance he covers is the height of each step multiplied by the number of steps.

Distance = 60 steps x 0.20 m/step = 12 meters

Work done = 588 N x 12 m = 7056 J

Power = work/time = 7056 J/40 s = 176.4 W ≈ 177 W

Therefore, the correct answer is B) 177 W.

A Man of Mass 60 Kg Runs Up a Flight