When oncoming air meets the leading edge of the airfoil (wing), some of it goes over the top of the airfoil and some of it flows underneath. The air flowing over the top of the wing has to go further than the air underneath, because it must join together again with the air that flowed under the wing at the far (back) side of the wing--physical laws act together to prevent or minimize vacuums in most cases.

To move a heavy object a few feet in height, the incline plane is the most efficient device (of those listed) to use.

4! (4 factorial) = 4 × 3 × 2 × 1 = 24.