Question
A boy weighing 50 kg climbs up a vertical height of 100 m. Calculate the amount of work done by him. How much potential energy does he gain ? Take g = 9.8 m/s2.
Solution
Mass of the boy, m = 50 kg
Acceleration due to gravity, g = 9.8 m/s2
Vertical height that the boy climbed up, h = 100 m
Work done by the boy = mgh
= 50 x 9.8 x 100
= 49000 J
= 4.9 x 104 J
Gain in P.E. = Work done = 4.9 x 104 J.
