Question

A stone of mass $m$ tied to a string of length $l$ is rotated in a circle with the other end of the string as the centre. The speed of the stone is $v$. If the string breaks, the stone will move

• A. along a tangent
• B. towards the centre
• C. away from the centre
• D. will stop

Answer 1

The correct option is A along a tangent

For any particle to be in circular motion, a centripetal force is required. For the case of stone, the centripetal force is provided by tension in the string. But as the string is cut, the tension in the string becomes zero, and the instantaneous velocity of the stone is along the tangent. So it will keep moving in the same direction (along tangent) due to inertia of motion rather than being in circular motion again.