Momentum: When a bowling ball hits a golf ball

huynhtn2

A mass that is significantly larger than another. The larger mass hits the stationary smaller mass. I don't understand why the smaller mass has a velocity of 2 times the larger mass after the collision.

Does it have something to do with v1(initial) - v1(final) = v2(initial) - v2(final)?

fzero

I don't believe that your equation is true. What is true is that the momentum and kinetic energy are conserved in the collision. You might try writing those conditions down in order to find an expression for the velocity of the golf ball after the collision.