1. The problem statement, all variables and given/known data An electron approaches a potential barrier 10eV high and 0.5nm wide. If the electron has a 1%chance of tunneling through, what must be its energy? 2. Relevant equations Transmission probability = [C/A]^2= [ 1 + (U^2 sinh^2(mu alpha))/(4E(U-E))]^-1 where U=potential=10eV E=energy of electron mu=sqrt(2m(U-E)/hbar^2) alpha = width of box = 0.5 nm 3. The attempt at a solution I've substituted everything in and fiddled for ages but I really can't rearrange to make E the subject of this formula. can anyone help?