The tennis ball is made from a mixture felt-rubber; the internal gas is air.
Nylon, and cork
when you run and try to hit the tennis ball
for spin on the ball
Phosphate is a mineral used in making soda.
If you mean a sink hole, then its calcium carbonate (CaCO3) ie limestone.
I have learned that graphite is used in the handle of the racket and that's why someimes you find black marks on your hand after playing for a while.
hard tennis ball
where can I find a used tennis ball machine with battery and A/c?
Prince
Slazenger tennis balls are used at Wimbledon.
A new tennis ball will bounce higher. Old tennis balls are considered "dead."
when you run and try to hit the tennis ball
Yes, there are. www.ebay.com, www.craigslist,com, and www.amazon.com all sell used tennis ball machines.
Head to SportsTutor.com. They have one of the best tennis ball machines you can buy. You can just head to good old Amazon.com, they have plenty of tennis ball machines for you to choose from. where can I find a used tennis ball machine with battery and A/C?
aluminum
for spin on the ball
a tennis ball, a baseball, a golf ball, a monkey skull
Cracked table tennis balls can be used for vehicular antenna-toppers.