Exploring the Coriolis Force: Real or Imagined?

[Ranku]

Is the Coriolis force actually experienced by an object, or is the object simply deflected in its path?

 

[anuttarasammyak]

Coriolis force is experienced by, and thus deflects the path of the object in rotating frame of reference.

 

[Ranku]

Coriolis force is experienced by, and thus deflects the path of the object in rotating frame of reference.

By experience, do you mean the object experiences resistance to the force, in the same way an object experiences inertial
force in response to an applied contact force?

 

[Hornbein]

Is the Coriolis force actually experienced by an object, or is the object simply deflected in its path?

I would say that it is the Coriolis pseudoforce. It is the result of inertia.

 

[anuttarasammyak]

do you mean the object experiences resistance to the force, in the same way an object experiences inertial
force in response to an applied contact force?

In rotating frame of reference centrifugal force and Coriolis force deflect the path of free moving object from the straight line. The free moving objects on the deflected path under centrifugal and Coriolis force get no stress. Even very fragile objects keep their shapes. It is obvious because they are at rest or moving at a constant speed in IFR.

 

[Ranku]

In rotating frame of reference centrifugal force and Coriolis force deflect the path of free moving object from the straight line. The free moving objects on the deflected path under centrifugal and Coriolis force get no stress. Even very fragile objects keep their shapes. It is obvious because they are at rest or moving at a constant speed in IFR.

To clarify, the objects the not feeling the Coriolis force, even though they are deflected by the force?

 

[Ibix]

To clarify, the objects the not feeling the Coriolis force, even though they are deflected by the force?

What do you mean by "feeling"? In frames where the Coriolis force exists it's like gravity - you can't measure it in any way, except that your velocity with respect to points that are fixed in the rotating frame is varying or you feel a contact force from such a fixed point.

 

[Ranku]

What do you mean by "feeling"? In frames where the Coriolis force exists it's like gravity - you can't measure it in any way, except that your velocity with respect to points that are fixed in the rotating frame is varying or you feel a contact force from such a fixed point.

Yes, that is what I was trying to clarify, the fact that the inertial mass of the object doesn't feel the Coriolis force, just like gravitational mass of an object doesn't feel the gravitational force, when it is in gravitational freefall. On the other hand, gravitational force is felt, when there is a counteracting contact force, such as the 'normal' force, when the object is resting on the ground; similarly, Coriolis force would also be felt if there is a counteracting contact force, in the form of an attachment to a fixed point on the rotating disc.

 

[vanhees71]

I can only once more point to the great video "frames of reference":

 

[Ibix]

On the other hand, gravitational force is felt, when there is a counteracting contact force, such as the 'normal' force, when the object is resting on the ground; similarly, Coriolis force would also be felt if there is a counteracting contact force, in the form of an attachment to a fixed point on the rotating disc.

You still don't feel either gravitational force nor Coriolis force in those circumstances - you feel the force from the contact point. If you adopt the non-inertial coordinates in which the the contact point (the floor or the rotating wall or whatever) is at rest, you interpret that contact force as being a reaction to some other force which you call gravity/Coriolis, but you can always adopt an inertial frame and interpret it as a contact force created by the non-inertial motion of the contact point.

 

[jbriggs444]

Coriolis force would also be felt if there is a counteracting contact force, in the form of an attachment to a fixed point on the rotating disc.

Minor nitpick here.

If an object is attached to a fixed point on a rotating disc then the Coriolis force in the rotating frame will be zero. Objects that are not moving relative to the rotating frame have zero Coriolis force. They will still be subject to centrifugal force, of course.

An object that is sliding "down" a radial track on a rotating disc will be subject to a non-zero force from the track. This force will be equal and opposite to the Coriolis force and will be regarded (in the rotating frame) as accounting for the fact that the radial trajectory has zero tangential acceleration.