Week 11: Light 389
Homework for Week
Problem 1.Physics Concepts
Make this week’s physics concepts summary as you work all of the problems in this week’s
assignment. Be sure to cross-reference each concept in the summary to the problem(s)
they were key to. Do the work carefully enough that you can (after it has been handed
in and graded) punch it and add it to a three ring binder for review andstudy come
finals!Problem 2.Derive Snell’s Law. You may use any method you like (there are several) but the way
it was done in class is probably the easiest).Problem 3.Derive the Doppler Shift:
f′=f 0(
1 ±vcr
1 ∓vcs)
for light sources or receivers moving in a vacuum, where the upper signs in both case
refer to approach and the lower signs recession. Note well that this is how the radar guns
police use to trap speeder work, how “doppler radar” used by weather forecasters works
that measure the wind speed of storms and can detect the occurence of tornados, and is
a technology used in a variety of medical imaging techniques including e.g. ultrasound.Problem 4.Derive Malus’ LawIt=I 0 cos^2 (θ) whereI 0 is the intensity of polarized light incident on
a polarizing filter at an angleθrelative to the transmission axis of the filter. I’d suggest
going back to the Poynting vector and expressing the intensityI 0 in terms ofE 0 , the
E-field amplitude of the incident polarized wave.Problem 5.Derive Brewster’s Formula (the expression for the angle of incidence for which reflected
light is completely polarized parallel to the surface).Problem 6.Draw pictures representing: