A mass less spring is hanging vertically. With no load on the spring, it has a length of 0.34 meter. When a mass of 0.63 kilogram is hung on it, the equilibrium length is 0.91 meter. At t = 0, the mass (which is at the equilibrium point) is given a velocity of 4.94 m/s downward.
At t=0 28 second, estimate what is the acceleration of the mass? (Positive for upward acceleration, negative for downward)