a 50 g tennis ball is screaming towards serena william’s racket at 90 km/h. if the ball ends up leaving her racket going the opposite direction at…

a 50 g tennis ball is screaming towards serena william’s racket at 90 km/h. if the ball ends up leaving her racket going the opposite direction at 120 km/h, determine the ball’s change in momentum. consider the direction serena hits the ball to be positive’