Question

An object of mass 5kg is taken from a height of 10 m to a height of 30 m. What is the increment in its potential energy? (Assume g = 10m/s^2)

(a) 500 J

(b) 1000 J

(c) 1500 J

(d) 2000 J

This question was addressed to me in an interview.

The above asked question is from Potential Energy topic in section Work, Energy and Power of Physics – Class 11

Answer 1

The correct option is (b) 1000 J

The explanation is: PE = m x g x h

m = 5 kg

g = 10 m/s^2

Let;

h1 = 10m

h2 = 30m

PE1 = 5 x 10 x 10

 = 500 J

PE2 = 5 x 10 x 30

 = 1500 J

Increment in PE = PE2 – PE1

 = 1500 – 500

 = 1000 J.