Question

Two bodies, A and B, have masses of 10 kg and 12 kg, respectively. If they have an equal momentum, what is the ratio of their kinetic energies?

Answer 1

M1 V1 = M2 V2 momenta of M1 and M2 are equal

10 V1 = 12 V2

V2 / V1 = 5 / 6

1/2 M2 V2^2 / (1'/2 M1 V1^2) = M2 / M1 * (V2 / V1)^2 ratio of energies

M2 / M1 * (V2 / V1)^2 = 12 / 10 * (5 / 6)^2 = 5 / 6 = .83