A certain string can withstand a maximum tension of 31 N without breaking. A child ties a 0.33 kg stone to one end and, holding the other end, whirls the stone in a vertical circle of radius 0.91 m, slowly increasing the speed until the string breaks.
(a) Where is the stone on its path when the string breaks?
at a random point on the path
at the lowest point on the path
at the highest point on the path
cannot be determined
(b) What is the speed of the stone as the string breaks?
m/s