1. The problem statement, all variables and given/known data 1D Potential V(x) = mw^2x^2/2, part of a harmonic oscillator. Suppose that the spring can only be stretched, so that the potential becomes V=infinity for x<0. What are the energy levels of this system? 2. Relevant equations 3. The attempt at a solution I argued my way though this problem by the following: We know that V(x) = infinity V(0) = 0 V(x) = 0 otherwise From our typical energy levels we know E_n = ħw(n+1/2) for n=0,1,2,3,... But there is a barrier at x =0. Therefore we need x=0 to have E=0. Energy levels are thus: E_n = ħw(n+1/2) with n=1,3,5,7,... One can see this though the wave function graphs: https://i.stack.imgur.com/rb340.gif Is that argued properly? Did I find the right solution?