Two people are standing on a 3.19-m-long platform, one at each end. The platform floats parallel to the ground on a cushion of air and like a hovercraft. The two people, the platform and a 3.16-kg ball are all initially at rest. One person throws the 3.16-kg ball to the other, who catches it. The ball travels nearly horizontally. Exclusive of the ball, the total mass of the platform and people is 194 kg. Because of the throw this 194 kg mass recoils. How far does the platform move before coming to rest again?