A weightlifter is lifting weights of mass 200 kg up to a height of 2 metres. If g = 9.8 m/s2, calculate:
(a) Potential energy acquired by the weights.
(b) Work done by the weightlifter.
(a) Given,
Mass, m = 200kg
Acceleration due to gravity, g = 9.8m/s2
Height, h = 2m
(a) We know,
P.E = mgh
= 200 × 9.8 × 2
=3920 J.
(b) Work done = Potential energy gained = 3920 J.
(Since, at any point above the surface of the ground, the work done in raising the body is numerically equal to the potential energy)