posted by Nala .
A tennis ball of mass 57. g bounces off a wall. Right before hitting the wall, the ball is moving to the right and up with vx=+40. m/s and vy=+10. m/s. Right after bouncing off the wall, the ball is moving to the left and up with vx=-35. m/s and vy=+10. m/s.
If the ball is in contact with the wall for 4.5 ms, what is the average force that the wall makes on the ball?
change of momentum normal to the wall
change of momentum parallel to wall
=m(vy1-vy0)=m(10-10) = 0 kg-m/s
Time = 4.5 ms
= rate of change of momentum
= -75*0.057/(0.0045) N