1. The problem statement, all variables and given/known data A handball of mass 668 grams is thrown straight against a wall with a speed of 13.36 m/s. It rebounds straight back out with the same speed. The average force exerted on the wall by the ball is 12 N. How long is the ball in contact with the wall? 2. Relevant equations FΔt = mΔv (?) 3. The attempt at a solution m = 0.668 kg, Δv = 0 m/s, F = 12N With the equation I used, the answer I get is 0 s, but the answer isn't 0 s. Can anyone tell me what the correct equation to use is? Or what I'm doing wrong?