The momentum of a body is increased by 20%.The percentage increases in kinetic energy is

Options

(a) 54 %
(b) 44 %
(c) 100 %
(d) 50 %

Correct Answer:

44 %

Explanation:

Increase in KE = p²/2m
New momentum = p + p/5 = 6p/5
KE(f) = [(6/5).p]²/2m = (36/25).(p²/2m)
ΔKE = (36/25).(p²/2m) – (p²/2m) = (11p²/252m)
Percentage increase = 44%