Given, velocity of first body v1 = v And velocity of second body, v2 = 2v
Since masses are same, kinetic energy is directly proportional to the square of the velocity (Kav2)
Hence, ratio of their kinetic energies is: k1/k2 = v12/v22 = v2/(2v)2 = v2/4v2 = 1/4 = 1 : 4