college physics
posted by Anonymous .
Now assume that the pitcher throws a 0.145 kg baseball parallel to the ground with a speed of 32 m/s in the +x direction. The batter then hits the ball so it goes directly back to the pitcher along the same straight line. What is the ball's velocity just after leaving the bat if the bat applies an impulse of 8.4 N*s to the baseball? I just cant figure out how to do this problem. Please help!

Impluse=change of momentum=finalmomentuminitialmomentum
Give the direction toward the plate as +, so initial momentum is +, impluse is  
i don't know!