A particle of mass m confined to a line of length L from z = 0 to z = L has energies: En = n^2 π^2 ħ^2 / (2mL^2) where n is a positive integer and corresponding normalised eigenfunctions ψn: ψn = √(2/L) sin(nπz/L). (a) If the particle is in the n = 2 state, evaluate the probability to find the particle between z = 0 and z = L/3. (b) At time t = 0, the wall located at z = L is suddenly pulled out to the position at z = 2L while the particle is in the ground state. This change occurs so rapidly that instantaneously the wavefunction does not change. Calculate the probability that the particle will be in the n = 2 state of the expanded line, for which the particle has the same energy as it had in the ground state. Use sin^2 θ = 1/2 (1 - cos 2θ) to do the integrals.