Centrifugal force (rotating reference frame)

Centrifugal force is a perfect example of the reaction force Isaac Newton predicted to exist. In LAW III, Newton wrote "To every action there is always opposed an equal reaction..." Every object traveling a curved path is having its velocity forcefully changed in the direction of the axis of the curve. The centripetal acceleration/Action force present is the cause of this action.

In an event where the object is being whirled in a circle by an attached rope, the centripetal acceleration/Action force is an external (contact) force present at the point of contact between the rope and the object. Equally present at this same point of contact is the object's centrifugal acceleration/Reaction force. Insertion of an ordinary tension spring scale will provide proof of the presence of an equal and opposite, action and reaction pair of real forces.

If these action and reaction forces are equal and opposite, why does the centripetal action force have its way as the cause of inward-directed acceleration? The answer is as straightforward as recognizing that the centrifugal force, as a true reaction force, is caused by and provides the LAW III predicted support for the event-causing centripetal action force. Thus it is not logical to expect the centrifugal reaction force to do anything more than provide support for the centripetal action force that represents its cause.

The same may be said about the acceleration/Action and acceleration/Reaction forces present in an event involving linear acceleration. In your car, you would not expect the forward-directed acceleration/Action force from the seat against your torso to be canceled by the equal and opposite rearward-directed acceleration/Reaction force from your torso against the seat. The a/R force from your torso is caused by and provides equal and opposite support for the a/A force from the seat while serving in no manner to reduce or cancel the event's acceleration.

The centrifugal reaction force present in circular events is often said to be "fictitious" or unreal. Our scale tells us otherwise. This popular confusion is based upon a general misunderstanding of the supporting role of a true reaction force which can never act as the cause of any event. Thus a centrifugal reaction force is always an outward directed force that is present in an event where the action of acceleration is always inward directed.

Ethan Skyler

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