A mass m on the end of a massless rod rotates with constant speed v in a homogeneous gravitational field. The [color=#1551b5]gravitational force[/color] acting on m is indicated in blue. The red forces are the components of the [color=#c51414]force the rod acts on m[/color]. The force indicated in black is the sum of the red and blue forces. This black force points from the mass to the rotation center and has constant magnitude which depends only on the speed v, the mass m and the length of the rod.
