Why skydivers don’t feel the big freefall feeling from the acceleration when skydiving if horizontal (X) and vertical (Y) motions are independent of each other?

Question

I’ve gone skydiving before, and you have maybe 1-2 seconds of that small drop in your stomach feeling before you reach terminal velocity at about 120mph. But that should only make sense if the plane you are jumping out of is going about 90 mph in the vertical direction right? I’m assuming it’s not, maybe flying 90mph in the horizontal axis. So can someone explain why there’s still not a huge change in acceleration to cause that drop in stomach feeling?

In: 3

Answer 1

Before you jump out of the plane, the plane is pushing up on you. When you jump, that force goes away suddenly. That’s an acceleration (at least, if you don’t want Einstein to describe General and Special relativity to you), which you feel. The plane isn’t pushing up on your feet, so your body isn’t pushing up on your stomach, so you feel your stomach move upwards(relative to you).

Then you also jump out into air travelling at 50 knots/miles per hour, or 25m/sec. You will start to decelerate in the horizontal direction as you are moving through the air in that direction but there is nothing to keep pushing you, but that force is at right angles to what your stomach is doing, so if anything it will add to the general weirdness you feel.

Then, as others have said, you start to speed up and the moving air is now pushing up on you, so now you are in a pretty normal 1G situation, with the moving air is pushing you up instead of the ground, so you feel pretty normal – except for your brain freaking out about all that nothing beneath you.