Physics
posted by Tom .
A 0.15 kg baseball is thrown towards a batter with a velocity of 40 m/s. The batter hits the ball and returns it directly back with a velocity of 60 m/s.
What is the change in momentum of the ball?

mass times change in velocity
.15 kg * 100 m/s
positive in direction of pitcher from batter 
The speed of a basketball as it is dribbled is the same when the ball os goping toward tthe floor as it is when the ball rises from the floor. A. Is the basketball's change in momentum equal to zero when it hits the floor? B. If not, in which direction is the change in momentum. Draw its momentum vectors before and after it hits the floor.