I'm trying to figure the velocity (and specifically the angle) of a squash ball (for example) after being hit by a racket. Simple case: say the ball is initially stationary (hanging in the air!) and the racket hits the ball "flat". That is the velocity of the racket it normal (perpendicular) to the face of the racket. Then it seems simple - the ball will move away with a velocity also normal to the face of the racket, in line with the velocity of the racket. More complex case: say the ball is initially stationary again, but this time the face is "open" or at an angle to the velocity vector of the racket. E.g. you are hitting it along a horizontal trajectory, but the face of the racket is not vertical, but tilted back, say 45 degrees. What angle does the ball come off the racket now? I'm not sure how to figure this out. The racket has strings - its not a flat surface. Most complex case: as above, but now say the ball has in inbound velocity. I need its outbound velocity in the ground frame of reference. I'm not sure its a simple case of doing vector addition of its inbound velocity to what would happen had it been stationary when hit. I also need the magnitude of the velocity. Will it be that of the racket + ball inbound - losses for heat etc.? Thanks for your help!