Two balls collide elastically head-on; one lighter ball has mass m and is moving at speed v, the other, heavier ball, is moving at speed - After the 2 collision, the lighter ball moves at speed 6v. Find the ratio of the masses, and express the final speed of the heavier ball in terms of v. Let m be the mass of the lighter ball and M be the mass of the heavier ball. Enter your ratio in the form of a fraction (do not simplify). The ratio of the mass of the lighter ball to the heavier ball is The final speed of the heavier ball in terms of v is