1. The problem statement, all variables and given/known data A ball moving westward at 36 m/s hits a wall and rebounds at 27 m/s, eastward. (a) What is the change Δv in the vector velocity? (This is effectively the velocity of the rebounding ball relative to an image of it passing through the wall unaffected. It’s not the same as the 9 m/s reduction in the scalar speed!) (b) Find the acceleration during the impact if that lasts 0.14 s. 2. The attempt at a solution For change in velocity I had 9 m/s eastward. I don't know if that is correct.