In Chapter 9, we will define the center of mass of an object and prove that its motion is described by the particle under constant acceleration model when constant forces act on the object. A gymnast jumps straight up, with her center of mass moving at m/s as she leaves the ground. How high above this point is her center of mass (a) s, (b) s, (c) s, and (d) s thereafter where a = and y = ?