A certain string can withstand a maximum tension of 43 N without breaking. A child ties a 0.37 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. Where is the stone on its path when the string breaks? at a random point, lowest point, or highest point on the path, or cannot be determined? What is the speed of the stone as the string breaks?