A person has a piece of (mass less) string of length 0.6 m with a ball of mass 0.05 kg at the end of it. The person starts to swing this device in a vertical circle with a center located 2 m above the ground. The tension in the string is kept constant and equal to 10 N. What is the kinetic energy of the ball at the bottom of rotation? What is the kinetic energy of the ball at the top of rotation? What is the dissimilarity in the gravitational potential energy between these two points?