No, you can't.
No. It is illegal for an eligable man to block a defender past the line off scrimmage if the ball is in the air.
No it is not legal to have any contact with the goalkeeper.
No. You can block the receiver up to 5 yards away from the line of scrimmage, but after that you can't stop them from running their route.
You have to be in mid air while a POW is on top of you.
A football with no air is heavier than a football with full air because the air adds buoyancy and makes it lighter.
yes. think about balloons: a ballon with helium will float while a balloon with good ol' air will sink
That's easy! You right click on where you want to place it.
Any patch of dirt with no opaque block above it (so only air, leaves etc) will grow grass after a while. If any block is covering it, blocking out the sun, then the block will remain dirt.
you must find a jump on the track. it only affects the ground and will not hurt you while in the air
newtons laws are contributed by while the foot ball is in the air inertia acts on it.
air is in the football
You do not ever want to block or restrict air flow to a return air grille.