Quote:
Originally Posted by raymor
The effects are indistinguishable. To understand both, we need to talk about G force. The effect we feel from gravity and centripetal force are both G force. G force is defined as proper acceleration relative to gravity. That could be linear acceleration, being pages back in your seat in a fast car, or centripetal G force as you accelerate toward to left on a circle track.
Thus in free fall you feel no G force. That's the weightlessness inside a diving plane or falling elevator. Standing on the earth, you feel your arms being pulled down by G force because the "normal" state is to be falling. By being motionless that's 1G acceleration upward relative to the reference state of falling. So that's how you feel G force related to gravity.
How does a centrifuge create G force? What's the acceleration? Let's say you're going due north at 100 mph. Your velocity in the westerly direction is zero. If you turn the wheel to the left, you're suddenly going west. Aha, you were going zero mph west, now you're going west at high speed. That increase in your westerly velocity is an acceleration. Remember G force is defined in terms of proper acceleration, so that's a G force.
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best answer yet, and you seem to have some grasp on this subject of all that have posted so far. but you still didn't answer my question, explaining the difference between the two.
let me take your answer a step further. You talk about G force in free fall. but that's not what I asked. I asked about circular motion and the force in it. If you spin - your arms fling out. you don't have to have gravity for that. It will happen in a vacuum in deep space with no gravity acting on you. the force acts like gravity in reverse (but can be used as gravity if your inside a spinning circle).
so how are they different?
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