Question1

Two identical spin-1/2 particles are confined within a cubical box with sides d=10^-8 cm in length. A short range attraction potential of strength V0=10^-3 ev exists between the pair of particles-e.g. acting when the distance between the particles is less than a=10^-10 cm. Using perturbation theory, compute the ground state energy and wavefunction.Take the mass of the particles to be the electron mass.

Question2

Rod, A which is 30 cm long, expands by 0.045 cm when heated from 0oC to 100oC. Rod B, also 30 cm long expands by 0.075 cm for similar change in temperature. A third Rod C, also 30 cm long is made up of the materials of rod A and B, associated end to end. It expands by 0.065 cm when heated from 0oC to 100oC. Compute initial lengths of rods A and B in rod C.