2. A ball of mass 0.50 kg is attached to a horizontal spring. The spring is compressed 0.25 m from its equilibrium and then released. The ball undergoes simple harmonic motion, achieving a maximum speed of 1.5 m/s. (a) Determine the spring constant. (b) Calculate the speed of the ball when the spring is halfway to its equilibrium point. (c) When the ball is halfway to its equilibrium point, what fraction of its energy has been converted from elastic potential energy to kinetic energy