# Terminal velocity & Zero G.

1. Jun 16, 2009

### pipersam

Hello everyone,

I'm in great need of an expert answer and havn't been able to find much help at all, so I am hoping I have come to the best place.

I have two questions regarding forces acting apon passengers in an aircraft.

I would like to know how passengers would experience a zero gravitational force inside a pressurized aircraft, which would be in a fixed pitch 90 degee descent. Does this have anything to do with terminal velocity? Can it be achieved at all? I'm ignoring the structual limits of aircraft, and I don't want this to be a factor.

Which leads me on the my second question, can the passengers inside a pressurized aircraft be accelerated beyond their own terminal velocity?

I'm sorry if sound stupid in asking these questions, but I really would like a clear explanation.

Sam Crawford.

2. Jun 16, 2009

### bucher

In order to achieve a net zero force on an object, all forces must either be zero or cancel each other out. If the plane were to do a climb (let's say about 45 degrees) before taking its dive, the passengers would feel weightless as the plane began to reach its maximum height (the plane would have to have slow down its turbines and begin pointing down gradually). What will happen then is that the forces of the plane on the passengers will zero out. Even though there still is the gravity from the Earth, the passengers will float around in the plane (because the plane and the passengers will be falling at the same speed) (the passengers' point of reference would be the plane). In order to experience a zero force at a 90 degree dive, the plane's turbines would have to be off instead of slowed down during the climb. The plane can only accelerate due to gravity. This doesn't have to do much with the terminal velocity of the plane (assuming that the aerodynamics and large mass allow this assumption to be true).