i did attempt the problem. spend half hour on it. I just didn't copy everything i wrote on paper. Thought it would be too messy on forum and no one would want to read all that junk.
The problem with you guys is that you assume the worst of people.
A tennis ball has a mass of 0.057 kg. A professional tennis player hits the ball hard enough to give it a speed of 44 m/s (about 99 miles per hour.) The ball moves toward the left, hits a wall and bounces straight back to the right with almost the same speed (44 m/s). As indicated in the diagram...