Take the “zero” of gravitational potential energy to be at the height y′0 (the equilibrium point; you may also use this as the origin for the vertical coordinate!), and calculate all th...Take the “zero” of gravitational potential energy to be at the height y′0 (the equilibrium point; you may also use this as the origin for the vertical coordinate!), and calculate all the energies in the system (kinetic, spring/elastic, and gravitational) at the highest point in the oscillation, the equilibrium point, and the lowest point.
