Momentum is calculated by taking the product of mass times velocity. Thus, a moving tennis ball would have a nonzero momentum. However, since a tennis ball has a relatively small mass, it would need to have a high velocity in order to have a large value for its momentum. Since velocity is a vector (having both a magnitude and a direction), momentum is also a vector. When a tennis player hits a tennis ball with his racket, he imparts a force onto the tennis ball, which changes the direction of its momentum to return it over the net. (The value for this change in momentum is called impulse, which is equal to the product of the force applied and the time for which it is applied.)
Disregarding the fact that that's a rather moronic question, momentum is required to maintain the movement of the ball through the air from side to side. Without momentum the ball would be stationary, along the the tennis rackets and players body. Which would defeat the purpose of the game.
They practise against what they call, "professional hitting partners". Of course, oftimes, they will simply hit up with their coaches or other pro players, when they are about.
When the players keep hitting the ball to each other, without missing the ball. The rally stops when someone misses it :)
There are many tennis players training in Florida because they have some of the best tennis players in the world including Bolliteri tennis academy.
A table tennis rally is the same as a rally in any other racket sport. A rally is a series of "passes" between the players, with players hitting legal shots in turn.
Yes there are lots of Australian Tennis Players.
The top number of tennis players in a game is 4.
Top Players' Tennis happened in 1989.
Top Players' Tennis was created in 1989.
Not hitting the ball