By how much does the tunneling current through the tip of an stm change if the tip rises 0.020nm from some initial height above a sodium surface with a work function w=2.28ev? (hint: let the work func

By how much does the tunneling current through the tip of an stm change if the tip rises 0.020nm from some initial height above a sodium surface with a work function w=2.28ev? (hint: let the work function equal the energy needed to raise the electron to the top of the barrier)