A properly inflated grid iron football holds 13 psi of air.
None. If it is fully inflated it will be full of air so there would be no room for any water.
If you mean a hot air balloon, it is the expansion of the air caused by the propane burner. If you mean any balloon, it is the ability of the material to hold the air or gas inside which keeps it inflated.
An NFL size football is inflated to 7-9 lbs that's all i know. Update: Actually, a correctly inflated ball is filled with air to a pressure of 12.5-13.5 psi.
Ok I dont know the answer but im stopping some wasteman saying "with air"
The rubber incasement the ball is made of as well as the composition of air withing when fully inflated causes a football to bounce.
An inflated football is essentially more aerodynamic than a deflated football. The inflated one would travel faster and a greater distance. However, if you dropped them both at the same time, they would it the ground at the same time, because gravity pulls everything downward at 9.81 meters per second squared (ignoring the effects of air resistance in this last case).
To inflate something is to fill it with air. You can do that with an air pump, yes. Some things can be inflated without pumps, such as hot air balloons. And some pumps don't pump air.
No, it is not. A football is inflated with air which gives is a lot more give than a hard baseball. A baseball is made of solid material.
The adjective 'pneumatic' means of or pertaining to air, gases, or wind; filled or inflated with air or gas.
By football I am assuming American football. It is a rubber bladder with leather sewn around it and then inflated.