A 0.25-kg mass at the end of a spring oscillates 2.2 times per second with an amplitude of 0.15 m. determine (a) the speed when it passes the equilibrium point, (b) the speed when it is 0.10 m from equilibrium, (c) the total energy of the system, and (d) the equation describing the motion of the mass, assuming that at , x was a maximum.