Task 10640.

In light inextensible thread is suspended a heavy ball. At what angle you need to take the thread from the equilibrium position, so that the following swing maximum strength thread tension was 3 times more than the minimum?
Detailed solution with a short recording conditions, laws and formulas used in the decision, the withdrawal of the calculation formula and the answer.
If you have any questions about the decision to write. I try to help.