Terrifying simulation reveals why you would not fall out of a rollercoaster if the bar came loose

A terrifying simulation demonstrates why you probably wouldn't fall out of a rollercoaster seat even if the safety bar failed.

Rollercoasters are fascinating from a physics perspective because they rely so much on gravity to be able to work - strap in because this going to get technical.

Scream if you wanna go faster! (Vintervit / Getty)

Rollercoaster work on two Newtonian principles - gravity and inertia.

As you gain height on that terrifying crank up the hill the potential force increases which will cause the coaster to accelerate after it goes over the hump.

The rest of the ride is an ingenious way to dissipate that energy in a thrilling, but safe, way.

Gravity acts on an object with a force of 1G, meaning you would accelerate at 9.8m/s if gravity was the only force acting on you.

The other factor is inertia, the principle that an object will stay either at rest or in motion unless another force acts on it.

For a simplified example - a car won't start moving unless you press the gas or slow down unless you apply the brakes.

These two forces interact to make rollercoasters work. Still with me?

The forces at the top of the loop are balanced (Soldt / Getty)

A simulation - shared to YouTube by Zack D. Films - shows how momentum is released when a coaster starts accelerating and the strange effect it has when the coaster goes around a loop.

This is all to do with gravitational force, or g-force, which keeps you in your seat when the speeding ride gets to the top of the loop.

While going up you are pushed down into your seat by the combination of inertia and gravity, but at the top of the loop these two factors balance out.

This is why at the top of a loop you might experience a brief feeling of weightlessness.

The coaster then accelerates down the other side before the force of gravity acting on you breaks your inertia.

Here's another way to visualize how this works using things you could have at home.

Let's say you took a small bucket and filled it part way with water, not loads but a little bit, before tying the handle to a length of string or rope and swinging the bucket in a circle.

As long as you keep enough momentum on the swing then the water in the bucket will not fall out, but if the force is not enough then the centrifugal (moving away from a centre) and centripetal (moving towards a centre) forces acting on the water stop, and it falls out.

Obviously this doesn't mean you should now go and ride a rollercoaster without a harness, just so we're clear.

But one thing you can do to get an impression of this next time you're on a ride is to see how much you are pushed into your seat and how much into your safety harness.

That is, if you can stop screaming.