Sir Isaac Newton (1642-1727), a mathematician and physicist, who according to the well-known story conceived the notion of gravity by seeing an apple falling in his orchard.

Johan Bernoulli (1667-1748), a Swiss mathematician, who discovered the secret behind a wing's lift.

Slow Down - We know this because the kite tugs on the strings as if it is trying to counter it.

Stall - Fall out of the sky.

Skin Friction Drag is the drag due to the friction between the air and the surface moving through the air. If you "slice" your hand through the air - palm parallel to the floor - your hand is experiencing mainly skin friction drag. The friction is experienced because your hand tends to try to pull the air along with it. To overcome this drag you need more wind but this makes the kite more difficult to fly.