A ball of mass 0.5 kg attached to a light inextensible string rotates in a vertical circle of radius 0.75 m, such that it has a speed of 5 ms-1 when the string is horizontal. Calculate the speed of the ball and the tension in the string at the highest and lowest points on its circular path. Evaluate the work done by the Earth’s gravitational force and by the tension in the string as the ball moves from its highest to its lowest point.