Rolling down an escalator...?

Question

ok, if someone started rolling down an escalator at lets say 5 mph and his speed increased at 10 mph every second. now the escalator is moving up at the same speed as the person falling. this happened until the escalator was going up at 200 mph and the person was rolling down at 200 mph. now if the escalator suddenly stopped, would the person come flying down the escalator at 200 miles per hour or would he just start rolling down according to the first equation, (starting 5 mph and his speed increased at 10 mph every second.)

Answer 1

The person would fly down the escalator.  This is because if the escalator just suddenly stops, the PERSON is still in motion.  And newtons first law states, "An object in motion will stay in motion unless acted on by an exterior force." So if he gets to go as fast as 200 mph, his velocity isn't going to just dramatically get reduced to his initial speed when the escalator stops.

Answer 2

The escalator confuses the situation because of the steps and the angle.

How about a conveyer belt at 45 degrees?

Now you have someone rolling down a very long conveyer belt that speeds up to match his speed, but in the opposite direction. until the person was moving at 200 mph (relative to an outside observer, not to the conveyer belt, I assume) and the belt is moving at 200 mph in the opposite direction.

Conveyer belt suddenly stopped.

Remember his speed was 400 mph relative to the belt. That's a lot of friction.

I think when the belt stopped, he would continue to roll on at 200 mph. He had a lot of momentum, and that can't go away.

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Answer 3

It depends on factors.

Is the person rolling down the escalator in friction with it?

If yes, then the sudden stop of the escalator will project the person downwards to some speed, mostly related to friction, but it will be far below 200mph.

If not, then the person is basically flying, then your question is invalid, since the person would be falling down with or without the escalator moving.

You can try a simple experiment;

1) Fold a letter size paper (8.5 x 11 inches) in three parts, ending in a folded paper of around 2.8 x 11 inches.

2) Compress well the foldings so the paper comes up very flat.

3) Lay the folded paper over a empty and flat desk

4) Position a long pencil close to one extremity of the paper and perpendicular to the paper, leaving both sides of the paper out of the paper.

5) Pull the paper under the pencil, but block the pencil to roll along with your other hand thumb and indicator fingers.

6) Pull the paper fast, the pencil will rotate in its shaft without moving.

7) When the paper gets out from under the pencil, the pencil will start to move away from your fingers.

That is friction accumulated in form of rotational movement.

The pencil will move but never as speedy as you pulled the paper.

Answer 4

I dont think that the escalator would have much, if any, effect on the falling individual. Since humans, or at least most humans, do not have wheels, we'd basically bounce down the escalator. Each bit of contact would not significantly effect the overall results due to the person's acceleration would increase while they were in the air.

Answer 5

I'm sure someone can do the math, but I say he would go flying off long before he hit 200mph.. but if he hung on he would most likely go flinging off if it stopped.

Answer 6

If your person had some sort of unfortunate scoliosis condition and therefore closely resembled a wheel and he was also coated in nearly frictionless grease he would enjoy the ride until the escalator was shut off, then roll away at 200 mph.  Because that's the speed he'd been going and now the escalator is just stairs.

Answer 7

the person will stop suddenly when the escalator stops.