Q. An old hunting weapon was a rock on the end of a string. The hunter would swing the rock in horzontal circles and then throw it. If the rock had a mass of 2.0kg and the 2.0m long string breaks when the tension is 60N, what is the fastest the hunter can swing his rock without breaking the string? (For this question take into account that the string will "droop" because of gravity. Include a diagram of the situation and a free body diagram of the forces).