Kinetic energy is (1/2)*mass*velocity2.
Work out (1/2)m1*v12 + (1/2)m2*v22 for the blocks before the collision and then after the collision.
If the energies are the same the collision was elastic; if energy after is less than energy before, it is inelastic; if energy after is greater than energy before, there is a gain in kinetic energy.
Kinetic energy is (1/2)*mass*velocity2.
Work out (1/2)m1*v12 + (1/2)m2*v22 for the blocks before the collision and then after the collision.
If the energies are the same the collision was elastic; if energy after is less than energy before, it is inelastic; if energy after is greater than energy before, there is a gain in kinetic energy.