Question:
A light and a heavy object have the same momentum. Find out the ratio of their kinetic energies. Which one has a larger kinetic energy ?
Solution:
K.E. $=\frac{p^{2}}{2 m}$
For same momentum $(p), K . E . \alpha \frac{1}{m}$
$\therefore \frac{(\text { K.E }) \text { light object }}{(\text { K.E. }) \text { heavy object }}=\frac{\text { mass of heavy object }}{\text { mass of light object }}>1$
Thus, K.E. of light object > K.E. of heavy object.