Question

A machine has a power of 20kW. How long will it take for it to lift a body of mass 10kg from the ground to a height of 100m? (Assume g = 10m/s^2)

(a) 1 second

(b) 2 seconds

(c) 3 seconds

(d) 4 seconds

This question was posed to me in quiz.

My question is taken from Power topic in division Work, Energy and Power of Physics – Class 11

Answer 1

Correct answer is (b) 2 seconds

Best explanation: Power (P) = Energy (E) x Time (t)

20,000 = (m x g x h) x t

 = (10 x 10 x 100) x t

t = 2 seconds.