Teacup physics.

As a query that is generic to nearly every park on the planet, I felt here would be the best place to pose this question. Can the theme park physics buffs of the forum break down for me what kinds of forces are in play on a spinning teacup ride?

I ask because the experience of the ride famously varies enormously depending on the speed and direction of spinning. A tame ride can become something extremely fierce and dizzying. What is the should you always opt for a cup on a saucer or are there hidden advantages to the loan cups on the large plate?

A certain speeds more than others, you have the effect of being flung out to the edges like a spirograph, whereas other times you feel more as if you are drawn into concentric circles. Can someone explain this phenomenon?

I would never go for the single cups on the main turntable. Always go for the double spin!

There are a lot of rides that use this idea. Basically as you are in the center you you are going slower as you get to the edge, you are on the outside of the main circle and are travelling faster. At into the fact your ride car is also spinning and yes it can get fairly extreme.

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It's all about a Huss Breakdance. They make teacups look like the children's rides they are.

To properly answer this question would take a long time as there's so much going on on a teacups ride.

Basically it's to do with the sum of centrifugal forces which arise when you have a mass (in this case you) spinning in a circle. Some people may say that there's no such thing as centrifugal force and it's really a centripetal force (which acts towards the centre of rotation) and the fact that you want to continue in a straight line. Technically, this is correct but it's easier to think of it as a centrifugal force.

As there are three rotating parts, these centrifugal forces add together or cancel each other depending on the position of you and your teacup.

There is an added complication in the fact that when you move towards the centre of the main turntable (usually the teapot), the centrifugal forces exerted by the turntable become less and the same goes for the cup and the saucer.

The reason that you experience such a range of forces even if you spin in exactly the same way throughout the entire ride is because you have three rotations that are happening at different speeds and you get what are known as phase relationships.

Basically if there's a mark on the edge of the cup, saucer and turntable and they all meet at the same point once every rotation, the three parts of the ride are in phase. However, the chances of this happening are virtually nil and every rotation of the turntable will see the cup and saucer arrive at a different position. The three parts of the ride are out of phase and this results in spikes of forces as the three rotations interact in different ways.

To show this properly would require graphs of sine curves but I won't do that unless you request it.

Basically, for maximum forces, spin in the same direction as the saucer and the main turntable. This way you get the centrifugal effect of the three rotations adding together at the outside edge.

If you choose to spin in the opposite direction, the rotations of the cup and the saucer have a cancelling effect and you get a moon dancing type ride in some ways similar to a twister at a fair.

The lone cups are a bad deal all round and are to be avoided.

I hope this has been useful. I think for me to explain any better would require diagrams.

Single cups with two of you in, both spinning it like mad if Marauders Mayhem at Towers is anything to go by.

My posts have this many mistakes in them?! Damn this Tapatalk milarky

Thanks ever so much for that post, CGM. It was extremely informative.

If anyone has a favoured technique for getting the most out of this highly variable ride, do share!

I've been thinking this over a little bit and I've realised that if you are rotating in the same direction as the turntable and your teacup has an unbalanced mass (which is most likely) the motion of the ride will actually assist your spinning. It's the principal which Huss Breakdances and Waltzers work on. If the unbalanced mass of your car is towards the middle of the table, as you reach the outside edge, the forces will throw the mass outwards sending the cup into a spin. So try to get everyone in your cup to squeeze round to the same side.

It might be a technique that requires tuning as it could potentially create consistently fast spinning or chaotic random bursts. I think a takeover of Marauder's Mayhem is required in the name of science.

if you can find the old toy called a spirograph then this can demonstrate what happens and the ride path on a teacup ride quite effectively. i sure there must be a demo video on YouTube somewhere.

saves all that mucking about with centrifugal forces which someone quite rightly says don't exists. centrifugal force is what it feels like when its centripetal acceleration is the actual physics.

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