A particle of mass m is subject to a gravitational field g and is also confined by a harmonic potential in the horizontal direction. The full 3D Hamiltonian is
H=2mpx2+py2+pz2+21mω2(x2+y2)+mgz
with the boundary condition ψ=0 at z=0.
(a) Show that the variables separate and write the total energy as a sum of contributions from each direction.
(b) Write down the allowed energies. What are the quantum numbers needed to label each state?