No it is not legal to have any contact with the goalkeeper.
No, you can't.
A football with full air is heavier.
Air resistance is a contact force because you are in contact with the air in order to apply that force.
Contact Air was created in 1974.
A goalkeeper is considered to be in control of the ball when... ...the ball is between the hands or between the hand and any surface (e.g. ground, own body) ...holding the ball in the outstretched open hand ...bouncing it on the ground or throwing it in the air A goalkeeper cannot be challenged for the ball even when in the process of throwing or punting it.
air is in the football
Yes, the football will appear "flat" as the air compresses in cold weather. Air expands as it warms, and so air in a football, tire, etc. will do the same.
air!
to hold air
Air Force Falcons football was created in 1955.
Air India - football club - was created in 1952.
a softball. a football is filled with air, and air isn't very dense. obviously.