Question

If momentum of a body is increased by 20%, then its kinetic energy increases by

• A. 36%
• B. 40%
• C. 44%
• D. 48%

Answer 1

Answer: (C)

44%

Answer 2

$K=\frac{p^2}{2m}$
$K=\frac{(1.2p)^2}{2m}$
$⇒\frac{K−K}{K}=(1.2)^2−1=0.44$
⇒ Kinetic energy increases by 44%
So, the correct option is (C): 44%