A pendulum comprises of a stone having mass m swinging on the string of length L and negligible mass. The stone has a speed of v0 if it passes its lowest point.
(i) Write down an expression for the speed of stone if the string is at some angle with the vertical.
(ii) Determine the greatest angle with the vertical which the string will reach throughout the stone's motion?
(iii) When the potential energy of the pendulum-Earth system is taken to be zero at stone's lowest point, determine the net mechanical energy of the system? Represent all your answers in terms of the given variables and g.