Spinning ball in vertical circle

Dec 2019
13
0
us
Hello, when I I spin a ball in a vertical circle, what forces do work on the ball?
 
Jan 2019
64
45
Assuming there is no external force driving the circular motion and ignoring any effects from friction, only the force of gravity does work.

In the case of an object attached to a string spinning in a vertical circle, the tension in the string does no work since the tension force is always perpendicular to the object's displacement.