Phy 361 – Modern Physics
Fall 2005
Homework Assignment 8
Due 11/1/05
There will be a quiz on Tuesday, November 1. The second exam will be on
Thursday, November 10.
Reading:
1. This week we discuss the quantum phenomenon of tunneling and its
applications. From Beiser study Section 5.10 and the Appendix to
Chapter 5, pages 193-197. In addition, you should study the notes
handed out in class last week.
2. We will begin the discussion of the solution of the Schr¨odinger equation
for the hydrogen atom. This week we will cover some of the material
discussed in sections 6.1 through 6.7 of chapter 6 of Beiser. We will
not go through all the math of section 6.2 and may not follow exactly
that same order as the text does.
Problems:
1. Problem 38, Chapter 5 of Beiser.
2. Electrons are accelerated from rest through a potential difference of
120 Volts and then focused into a well collimated beam. The electrons
in this beam travel freely from −∞ towards +xuntil at x= 0 they
encounter a rectangular potential energy barrier of height U0= 130 eV.
10% of the electrons are transmitted through the barrier. What is the
width of the barrier?
3. A 60 −eV electron is trapped between negligible-width capacitors
charged to 250 Volts (each capacitor has an exit hole). How far does
the wavefunction of this electron extend beyond the capacitors?
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