Phy 133 - Assignment 4:
A. 1.
2. n = tan θp So, θp = arctan 1.309 = 52.6˚ (ans)
B.1. The transmission axis should be vertical. The component of E parallel to
the reflecting surface is reflected more strongly. Since these reflecting surfaces
are usually horizontal, the reflected glare would have E horizontal.
2.
C. 1. The amount a wave diffracts depends on its wavelength, and the
wavelength of light is a lot less than sound’s. (Diffraction is significant if the
obstacle is roughly the size of the wavelength or smaller. Light will diffract
around very small objects. Ultrasound (sound with a very short wavelength)
will not go around a corner.)
2.
D. (a) Grating equation: m  = d sin
m = 3 (3rd order)
(3) (5.00 x 10-7 m) = d sin 32°
d = 1.5 x 10-6 = 2.83 x 10-6 m = 2.83 x 10-4 cm
sin 32°
Slits per cm = 1/(cm per slit) = 1/(2.83 x 10-4) = 3.53 x 103 ans.
(b) From the grating equation: sin m d
Try larger and larger values of m until sin passes 1. The sine function can’t
ever be more than 1, so that shows you the largest possible m.
sin (5)( 5.00 x 10-7 m)/(2.83 x 10-6 m) = .883 ok
sin (6)( 5.00 x 10-7 m)/(2.83 x 10-6 m) = 1.06 nope.
So, five orders can be seen on each side, plus the central maximum makes 11
maxima altogether.
E. 1. The light is polarized in different directions.
2.
F.
Let m = the number of wavelengths in the cylinder when empty. (total going in
both directions.)