Obtain the expression for the temperature dependence of the mean time between two collisions of conduction electrons with vibrations of crystal lattice, t, using classical approach. assume that the density of scattering centres is the same as the atomic density and that the mean speed of electrons does not depend on temperature. the average kinetic energy of atoms is 2 kt and average energy of atomic vibrations is 4 matom a wf, per degree of freedom. clearly justify each step.