A hypnosis clock has a mass of 0.2 kg and hangs on a string with a length of 0.35 m. The hypnotist initially oscillates with the clock slowly with an amplitude of 2 cm. Then he begins a forced oscillation such that the amplitude is equal to a quarter of the length of the string. At least how many oscillations does it take for this to happen if the hypnotist adds 
of energy with each oscillation? Assume that we are dealing with a simple pendulum.
