What would happen if...?

Question

A person was in a disk-shaped vehicle, and the floor spun around? As the vehicle accelerates forward, the disk spins at an RPM equal to that of the rate of acceleration? What effect would the direction of rotation of the disk relative to the motion of the vehicle have on the effect? Would the person's inertia cause him to stick to the wall, be "thrown back", or neither?

I know, this is weird, but I want to know.

What would be the physical effects on the person? Could he withstand more or less acceleration in this situation?

By the way, the "forward" motion is considered to be in the direction of the wall in front of the passenger inside the vehicle.

Could there be a way to move the vehicle and/or person, or disk so that the physical effects of acceleration , such as seats that move back and forth as the disk spins?

Answer 1

This would depend upon which direction was considered to the observer. If forward was the direction of the cieling, since acceleration is indistinguishable from gravity and there are 2 forms of acceleration here, one would feel "gravity" from the floor and the walls, so the observer wouldn't move much, he would just be tugged by accelerating forces from all sides and the floor. If forward was the direction of a wall, the observer would feel "gravity" from all sides, but would feel it more intense at the wall opposite of the front direction, so the observer would be thrown back into this wall the most.

At the very least, anyone inside this spaceship would feel very dizzy. If the rate of acceleration was fast enough, anyone inside would be torn apart (or the spaceship could be torn apart) or crushed by accelerative forces, which seem to be exactly like gravity according to Einstein.

Answer 2

When you say the RPM is equal to the rate of acceleration, I suppose you mean that the person's orbital speed around the center provides a centrifugal force equal to the force exerted by the vehicle's linear acceleration.

Let's consider four positions. First is when the person is at the front of the vehicle, relative to its direction of travel. That will be zero degrees. The other three positions, counting clockwise will be 90, 180, and 270 degrees. In the first position, the centrifugal force would be canceled out by the forward acceleration. Here, the passenger would feel no effects. At 90 degrees and 180 degrees, he would feel a force pulling him at 135 and 225 degrees, respectively, a vector of the two accelerations acting upon him.
At 180, he would feel double the effect of the acceleration, pulling to the rear.
If he is facing the center of the disk, he would feel no tug at zero degrees. Then a tug would start pulling him forward. The pull would constantly increase and change directions as he rotates, reaching its maximum when he is at 180, at which time it would be pulling him straight back. Reverse for the second half of his rotation.
Some carnival rides give the same effect, but it is achieved by two rotations. The big rotation simulates the forward acceleration of your model, then the pods or disks each rotate in their own little circles. (Sorry if I ruined your idea for a carnival ride.)

Answer 3

It's not clear exactly what you're asking. RPM is not a measure of acceleration. Picture a 'flying saucer' in space. You sit with your back to the rim. The craft spins at a constant rate chosen so the centripetal acceleration is 1G. This would be reasonable for a large space station as a form of artificial gravity. You would feel almost the same as you would 'sitting' in a chair rotated 90 degrees so its back is on the floor on earth.

Now accelerate this vehicle with a constant 1G acceleration toward Andromeda, with its axis of rotation perpendicular to the direction of this acceleration. When you face Andromeda, you feel 2G acceleration. When you face away from Andromeda, you feel 0G acceleration. It would be a dizzying ride indeed. Now increase the acceleration to 2G. Now your acceleration varies from 3G to -1G. With each rotation, you are smashed to the wall at 3G, then dragged along the wall, then leave the wall as it accelerates away from you, then smashed back into the wall. Go to a laundromat and watch the clothes inside a tumble dryer.