Question

The iron ball shown below is being swung in a vertical circle at the end of a 0.6 meter string. How slowly can the ball go though it's too position without having the string go slack?

Answer 1

Given,

Radius(r) = 0.6m

First draw the Free body Diagram:

The forces acting at the top will be Weight and the tension (Downward) and the forces acting at the bottom will be Centrifugal Force (Upward).

So,

Forces acting downward = Froces acting upward

Now, the string will slack just before the tension. So, Tension(T) becomes zero. The above equation becomes: