Centrifugal Homepage

Question: What causes centrifugal force?

(Posted by: CJ Johnson on 2009-05-31 22:01:12)

I understand that it is caused by spinning, but in relation to what is the body rotating if everything is relative? What is it spinning relative to? Is it the energy added to an object to increase its spin that decides whether one can say that it is indeed not static in regards to spin? Do you mean to draw similarity between centrifugal force and geosynchronous orbits? If so, that doesn't answer how one can say that the object isn't static in regards to spin, as you could say that everything else is in orbit and the body not spinning. Do you see where I am confused? Is it the energy that is required to change the rpm of the body that determines wether it is spinning? Ok, I think I understand know. Thank you.

Posted by: Scott on 2009-05-31, 22:15:13

"Spinning " is relative to the body's center of rotation. In the case of a spinning sphere, the sphere is spinning around its center. The centrifugal force comes from the fact that a point on the body is constantly being accelerated. Its *speed* may be constant, but its direction of motion is always changing, so the *velocity* is changing, which requires an acceleration. From Newton's laws, any acceleration requires a force, and in this case, it's called "centrifugal force ". Centrifugal force is often called a "fictictious force " or an "inertial force ", because it only comes about in rotating systems, not linear systems, so it's not the same as an object being linearly accelerated due to a conventional applied force like a rocket motor or a push from a hand.

Posted by: dewanbagh on 2009-05-31, 22:23:13

Centrifugal force does not exist in a linear frame of reference. The only force active is the centripetal force, which is caused by whatever is holding the object in orbit.

Posted by: doug_donaghue on 2009-05-31, 22:26:21

It's caused by centripital acceleration in a rotating system. Doug