Rods of length 4r and 2r are rotating horizontally in the shape of a cross. Assume that four tip of the rod each has mass point of mass m, and the mass of the rod is zero. Tension (centrifugal force) acting on the rod is a true force.
The formula for centrifugal force is F = m v^2/r. And as Newton's third law of motion shows, centrifugal force is an action and centripetal force is a reaction. The magnitude of the force is the same. The two are true forces.
Tension is centrifugal force, an effect of Newton's third law of motion, and centripetal force is a reaction. The two are true forces. Rotational motion can be boiled down to accelerated motion and non-accelerated motion (including absolute rest). Frame will be the celestial sphere and the aether.
