Question

2) If momentum of two bodies are equal, will their kinetic energies be equal, explain.
NO SPAM PLEASE!!​

Answer 1

You see , the momentum of a body of mass M and velocity V is given by P= MV.

The Kinetic Energy value is given by 1/2 MV^2.

=> Kinetic Energy K.E = 0.5 (MXV)XV .

=> K.E = 0.5(MOMENTUM)XV.

=>K.E is directly proportional to momentum.

Consider 2 bodies having equal momentum , 2 cases may arise...

Case-1 MOMENTUM IS EQUAL BUT..

both have same mass and same velocity, in this case , the velocity of both the bodies are also equal . So the Kinetic Energy is definitely equal in this case.

Case-2 MOMENTUM IS EQUAL BUT..

If the mass of both the bodies are not equal , neither the velocities are equal . (In this case let's say the velocity of  first body  is 5 m/s the other body is 3 m/s , but the mass of the first body is 3 kg and the other body is 5kg). Notice that the momentum of both the bodies are still same...BUT , since The K.E is given by product of (0.5 X VELOCITY X Momentum ) , even though the  momentum is same , the velocities are different , so the Kinetic Energy will also be different.

Hope this helped.