82. (a) The rate at which incident protons arrive at the barrier isn=1.0kA/1.60×10−19C=6.25×1023/s.LettingnTt= 1, we fnd the waiting timet:t=(nT)−1=1nexpÃ2Lr8π2mp(U−E)h2!=µ16.25×1023/s¶expµ2π(0.70 nm)1240 eV·nmp8(938 MeV)(6.0eV−5.0eV)¶=3.37×10111s≈10104y,which is much longer than the age oF the universe.(b) Replacing the mass oF the proton with that oF the electron, we obtain the corresponding waitingtime For an electron:
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This note was uploaded on 11/12/2011 for the course PHYS 2001 taught by Professor Sprunger during the Fall '08 term at LSU.