Simple Physics

by Jan Meyer

What does the path of a ball released from an aircraft look like when observed from the aircraft?

The ball travels backwards and down from the plane.

What does the path of a ball released from an aircraft look like when observed from the ground?

The ball travels forward and down. Eventually the forward motion stops and the ball travels straight down.

If a second ball with twice the diameter of the first ball was released from the same plane under the same conditions, what would the second ball's path look like compared to the path of the first ball when observed from the plane?

The larger ball would travel backwards faster.

---when observed from the ground?

The larger ball would not travel as far forward as the first ball.

These questions relate to jumpers as they leave an aircraft. The more air you catch on exit the smaller you forward throw will be. The less air you catch, then larger your forward throw will be.

Originally published in Sport Parachutist's Safety Journal V2, #5 Jan./Mar. 1991.
©Copyright 1991, 1996 by Jan Meyer. Republished with permission.