Book 28, Question 9
How hard should a ball be pumped for different sports?
Each sport has its own air pressure.
Basketballs are pumped to about 8 pounds per square inch, so they bounce well off a hard floor. Volleyballs are pumped to just 4 to 5, so they are soft for hitting with hands. Soccer balls are pumped higher, so they travel far when kicked. Too flat and a ball feels dead, too hard and it hurts.