A pendulum consists of a 320-{\rm g} solid ball15.0 {\rm cm} in diameter, suspended with an essentially mass less string 60.0 {\rm cm} long. Compute the period of this pendulum, treating as a simple pendulum. Compute the period of this pendulum, treating as a physical pendulum. Hint: Remember the parallel-axis theorem. How much error is introduced with the simple pendulum approximation?