A light and heavy body have equal momentum. Which one has greater kinetic energy?
The correct option is
A
Light body
Assume the weight of light body is m1 and the weight of heavy body is m2 and momentum is p1 and p2 respectively. Since momentum is equal then p1 = p2
We know, Kinetic energy = P22m
Kinetic energy of light body = P122m1
Kinetic energy of heavy body = P222m2
Given p1 = p2
Ratio of kinetic energy of light and heavy body = P122m1P122m1 = m2m1
Given ( m2 > m1 )
KE1KE2=m2m1
KE2<KE1
So, the kinetic energy of lighter body is higher than the kinetic energy of heavier body.