Consider the diffusion of a species i by a vacancy mechanism along a direction with an external driving force present. The distance between two closest lattice sites of the species i is 3.0 . The change in activation barrier over the distance between two nearest neighbor lattice sites due to the potential gradient is 1.110-4 eV. The jump frequency of the species i at 1,400 K is 109 Hz a) What is the probability that a jump contributes to drift motion? b) What is the frequency of drift jumps? c) What is the drift velocity?