The Physics of Roulette: Exploring Centrifugal Force

In summary, the wheel spinning in the opposite direction does not increase the ball's centerpetal force.
  • #1
a.mlw.walker
148
0
I am reposting this post because i forgot I had already posted a topic with the same subject, I study physics at uni, but spend my weekends down the casino on the roulette table. I tried to explain to my friend that the reason roulette works is that the centrepetal force of the ball is great than the force exerted by gravity, therefore the ball stays in the wheel. when it is less than the force exerted by gravity it will fall.

but does the wheel spinning in the opposite direction increase the balls centrepetal force. ie if the ball stayed still and the wheel span would there be a centrepetal force on the ball. what are the equations here.

also does all this mean that the ball will always fall out of the wheel at the same speed, because the moment the centrepetal force drops below the gravitaional force it will fall, and the centrepetal force is reliant on the speed.

odd question i know but its irratating me

alex
 
Physics news on Phys.org
  • #2
Newton's laws of motion are only true in inertial coordinate systems (those that are not accelerated).
Among all rotating coordinate systems with a common origin only one can be inertial. All other are accelerated, except at the origin. So rotation of the wheel has no effect on angular acceleration, only angular velocity in inertial coordinate system counts. Ground system is (aproximately) inertial system, since the rotation of the Earth is very slow.
I have not played roulette yet, but if it works like you described, then the ball will always fall down with the same speed. But the time when this happens can be influenced by the speed of the wheel (more friction).
Also the starting velocity is probably random enough that the outcome can't be predicted.
 
Last edited:
  • #3
If the ball is not moving in circular motion, it is not experiencing a centripetal force -- the concept does not make sense. Centripetal force is whatever force causes the accelleration necessary for centripetal motion. Without motion the question makes no sense.

It's best to think of in terms of accelleration. If the wheel is moving under the ball but the ball is not moving, he ball is not accellerating.
 
  • #4
… rolling or sliding … ? … place your bets now … !

a.mlw.walker said:
but does the wheel spinning in the opposite direction increase the balls centrepetal force. ie if the ball stayed still and the wheel span would there be a centrepetal force on the ball. what are the equations here.

Hi alex! :smile:

I think the simple answer is that the only difference which the direction of rotation can make is to add a tangential force.

This can make no direct difference to the (radial) centripetal acceleration.

All it could do is make the make the speed of the ball less, through friction.

Does anyone know whether the ball on a roulette wheel rolls or slides? :smile:
 

1. What is centrifugal force?

Centrifugal force is a fictitious force that appears to act on objects moving in a circular path. It is caused by inertia and the tendency of objects to continue moving in a straight line.

2. How does centrifugal force affect a roulette ball?

As the roulette wheel spins, the ball is subjected to centrifugal force, causing it to move in a circular path around the wheel. This force also affects the speed and direction of the ball's movement, ultimately determining where it lands on the wheel.

3. How does the speed of the wheel impact the centrifugal force on the ball?

The faster the wheel spins, the greater the centrifugal force on the ball. This means that a faster spinning wheel will result in a faster moving ball, making it more difficult to predict where it will land.

4. Can the physics of roulette be used to predict the outcome?

While understanding the physics behind roulette can give a general understanding of how the game works, it is not possible to accurately predict the outcome of a spin. There are many other factors at play, such as air resistance and imperfections in the wheel, that can affect the ball's movement.

5. Are there any practical applications for understanding the physics of roulette?

The study of the physics of roulette can be applied to other areas of physics, such as understanding circular motion and the principles of inertia. It can also be used in the design and construction of other rotating machines and devices. However, it should not be relied upon for any practical use in predicting the outcome of roulette games.

Similar threads

  • Introductory Physics Homework Help
Replies
12
Views
478
  • Other Physics Topics
Replies
7
Views
6K
  • Other Physics Topics
Replies
2
Views
3K
  • Other Physics Topics
Replies
2
Views
901
  • Classical Physics
Replies
2
Views
908
  • Other Physics Topics
Replies
7
Views
3K
  • Classical Physics
Replies
2
Views
648
  • Sci-Fi Writing and World Building
Replies
5
Views
1K
Replies
15
Views
2K
  • Other Physics Topics
2
Replies
38
Views
6K
Back
Top