Question

A small pebble tied at one end of a string is placed near the periphery of a circular disc, at the centre of which the other end of the string is tied to a peg. The disc is rotating about an axis passing through its centre.
What will be your observation when you are standing at the centre of the disc? Explain.

Answer 1

When we are standing at the centre of the disc, we observe that the pebble is stationary in front of us as the centrifugal force on the pebble balances the centripetal force provided by the tension in the string.