If the speed of the ball after it bounces, vyf, is 75\% of the speed right before it hits, what was the impulse the floor delivered to the ball? If the ball interacts with the floor for a time ...If the speed of the ball after it bounces, vyf, is 75\% of the speed right before it hits, what was the impulse the floor delivered to the ball? If the ball interacts with the floor for a time period Δt, find an expression for the ratio between the average force the floor acted on the ball with to the weight of the ball mg, in terms of vyi, vyf, g, and Δt.