Rubber band and a Merry Go Around

[MPavsic]

TL;DR Summary

Oscillation, rotation, rotating reference frame

Maybe someone already did this experiment?
We have rubber band stretched and attached to the fence of Marry Go Around. When Marry is not rotating we are oscillating rubber band vertically, and oscillation remains vertical.
What would happen if we oscillate the rubber band vertically when Marry is in rotation? What will happen, would it tend to oscillate horizontally?

 

[A.T.]

What would happen if we oscillate the rubber band vertically when Marry is in rotation? What will happen, would it tend to oscillate horizontally?

As soon the centrifugal force induces the horizontal component, the Coriolis force will make it go in loops.

 

[sophiecentaur]

Summary: Oscillation, rotation, rotating reference frame

Maybe someone already did this experiment?
We have rubber band stretched and attached to the fence of Marry Go Around. When Marry is not rotating we are oscillating rubber band vertically, and oscillation remains vertical.
What would happen if we oscillate the rubber band vertically when Marry is in rotation? What will happen, would it tend to oscillate horizontally?

A simple diagram could help a lot here. It isn't clear what you are suggesting.

 

[MPavsic]

Thank you A.T.
My thinking was; If the movement of the rubber particle is parallel with spin axis of the Marry Go Around than I should not get any Coriolis force and rubber particle oscillation stays in vertical position.
As the movement of rubber particle is not limited to move only in vertical line, than loops are what I should observe.

 

[sophiecentaur]

than loops are what I should observe.

The shape of the cross section of the band and the fixings will cause the band to have vertical and horizontal motion very soon. The almost identical periods of the V and H oscillations will mean that vibrational energy will be constantly exchanged from one mode to another. This happens for all strings (but less obviously for some tapes, for which the frequencies of the two modes are very different).
Perhaps a different oscillator would better show the effects you are after - say a mass on a spring.

 

[A.T.]

Thank you A.T.
My thinking was; If the movement of the rubber particle is parallel with spin axis of the Marry Go Around than I should not get any Coriolis force and rubber particle oscillation stays in vertical position.

Correct, but the centrifugal force will deflect it from the vertical direction.

As the movement of rubber particle is not limited to move only in vertical line, than loops are what I should observe.

Yes, but by loops I didn't necessarily mean closed loops.

 

[MPavsic]

I think, I understand. If oscillation of rubber band is vertical, the Coriolis force will make the rubber particle wobble, not circling, between +Y and -Y axis and will eventually dump in -x and +x axis.

 

[sophiecentaur]

If oscillation of rubber band is vertical, the Coriolis force

To cause Coriolis Force, the motion needs to be radial. It won't be there if the motion is parallel to the axis of rotation. (Or have I misunderstood what you are saying?)

 

[A.T.]

If oscillation of rubber band is vertical, the Coriolis force will make the rubber particle wobble, ...

Not the Coriolis force alone. You need the centrifugal force to deflect it from the vertical direction.

 

[MPavsic]

To cause Coriolis Force, the motion needs to be radial. It won't be there if the motion is parallel to the axis of rotation. (Or have I misunderstood what you are saying?)

The Coriolis force of rubber band particles can be radial or tangential to the center of local rotation, and not, as we concluded paralel.

 

[sophiecentaur]

The Coriolis force of rubber band particles can be radial or tangential to the center of local rotation, and not, as we concluded paralel.

Doesn't "vertical" mean parallel to the axis and not radial or tangential?
But, as @A.T. has implied, centrifugal force will cause radial motion as the band oscillates vertically.

 

[MPavsic]

Sure, vertical = paralel. A.T. gave me answer which is valid for both motions, radial and tangential. This is how I understand my problem.