歡迎來到Yogi老師解題給你看，今天我要講解的是AP Physics C Mechanics的問題
A pendulum consists of a 2.1 kg stone swinging on a 3.6 m string of negligible mass. The stone has a speed of 7.6 m/s when it passes its lowest point.
(a) What is the speed when the string is at 60° to the vertical?
(b) What is the greatest angle with the vertical that the string will reach during the stone’s motion?
(c) If the potential energy of the pendulum–Earth system is taken to be zero at the stone’s lowest point, what is the total mechanical energy of the system?