DUE  FEBRUARY 25, 2010





(1)      Two grey reflecting surfaces 1 and 2 at temperatures T1 and T2, have flux emittances ε1(2π) and ε2(2π) and flux reflectances ρ1(2π) and ρ2.(2π). The surfaces are flat, parallel, and separated by a transparent medium. Surface 2 is above surface 1.

Show that the upward and downward fluxes are given by:

F(+) = ε1σB T14 + ε2 ρ1 σB T24

                                                                        1- ρ1 ρ2


        F(-) = ε2σB T24 + ε1ρ2 σB T14

                                                                        1- ρ1 ρ2



(2) Calculate the rotational constant, B, for the electronic ground state of molecular hydrogen, H2. The inter-nuclear separation is re = 1.059 x10-10 meters.

Repeat the calculation for molecular oxygen for which  re = 1.42 x10-10 meters and contrast this value with that for H2.


(3)      A molecule has both rotational and vibrational quantized energy levels. Derive the formula that describe the energy of these levels, and discuss where in the electromagnetic spectrum one might expect to see transitions between these levels.