Physics
posted by Gharib .
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?
(I drew the diagrams and tried to use Pythagorean theorem but did not work for some reason.)
thank you.

change of velocity= Vfvi=35x+10y(40x+10y)= 75m/s in x direction
force*time=changemomentum= mass*(75m/s)
solve for force. 
Thanks Bobpurley, I didn't know it was that simple.