A spring with spring constant k is suspended vertically. A model goose of mass m is attached to the unstretched spring and then released so that the bird oscillates up and down. Ignore the friction, air resistance, and mass of the spring. Calculate the kinetic energy, the elastic potential energy, the gravitational potential energy, and the total mechanical energy (total energy) at (a) the point of release and (b) the equilibrium point. Take the gravitational potential energy to be zero at the equilibrium point.