Consider a quantum particle of mass m and kinetic energy E > 0 encountering an abrupt potential drop -Vo. Thus the potential is V(x) = 0 for r 0 (with Vo > 0). For particles incident from the left, first obtain a general form for the reflection coefficient R. Simplify the expression for the particular case if E = Vo/3. (Hint: match boundary conditions at r = 0)