A light and heavy object have the same momentum. Find out the ratio of their Kinetic Energies. Which one has a larger Kinetic Energy.

Assume both the particles have mass M and m and having speed v and v' respectively.

Say M>m.

According to question both particles have same momenta.

That means p = Mv = mv'

Also corresponding  KE = 0.5 M v² =  (Mv)²/2M = p²/2M

and KE'  = 0.5 mv'2 = (mv')²/2m = p²/2m

Light particle (m) has more kinetic energy than that of heavier particle(M).