On a personal level, it all depends on your skill.
As a comparison, the fastest a professional has hit a forehand was 120 mph (by Gael Monfils), and 155 mph on a serve (by Andy Roddick).
Yes, of course. The material a tennis ball is made out of is porrus. That is why tennis balls go flat.
120 mph
A new tennis ball will bounce higher. Old tennis balls are considered "dead."
An example might be - Tennis is a fast-paced sport. Another example is - The tennis ball shattered the window.
It will go as fast as it's terminal velocity
in hours or days
It depends. If a tennis balls are hit with the same amount of force, then the dry tennis ball will travel faster and farther. However, if the two tennis balls begin traveling at the same speed, then the dry tennis ball will slow down more rapidly than the wet tennis ball. The reason is the added mass of water. It would take more force to make the wet tennis ball fly as fast as the dry, but the added mass also requires more force to slow down the wet ball.
180 kilometers per hour
a tennis ball
You need to know the area of the glass, its span, how it is supported, and how thick it is; also you need to know the stiffness of the tennis ball; so this is a complex problem.
A tennis ball.
A tennis ball.