Answer:
The tension in the string is quadrupled i.e. increased by a factor of 4.
Explanation:
The tension in the string is the centripetal force. This force is given by
m is the mass, v is the velocity and r is the radius.
It follows that , provided m and r are constant.
When v is doubled, the new force, , is
Hence, the tension in the string is quadrupled.