Question

A stone tied to string is rotated in a vertical circle. The minimum speed of the stone at the bottom most point so that it just completes the vertical circle.

• A. Decreases with increasing mass of the stone
• B. Is independent of the mass of the stone
• C. Decreases with increasing in length of the string
• D. Is independent of the length of the string

Answer 1

The correct option is B Is independent of the mass of the stone

The minimum speed with which the string must be rotated so that it completes the vertical circle is give by
$u=\sqrt{5Rg}$ (for lowest point of vertical loop)
So, we can say that it does not depends on the mass of the stone.