Which has greater force fly hitting windshield of rapidly moving car or the force of windshield hitting fly? explain

The force applied on the fly and the windshield are equal based on Newton's Law of Action and Reaction. the difference between them is that the fly's body does not have enough mechanical strength to withstand the force but the windshield does.

If there was no gravity then their would be no downword force on the football to have it return the the grownd, and if there was no friction (mainly air friction) then there would be no opposing force the stop the ball from moving through the air allowing the ball to travle ∞.