Ch. 38 3 7 19 43 42 47

Answers
19. Let s = the separation of the boats.

Let x = the distance to the National Guard ship. Thus,

The image is on a antenna for the detector on  the Guard  ship. The slit width shown represents the diameter D of the antenna. Now,


Set this angle, which is the minimum for resolution inside the detector, equal to the expression given in section 38.9 for circular apertures. Remember, you must  calculate the wavelength from the frequency and the speed of light!
43 . The relationship between the intensity I0 before passing through the polarizer and I, that after the light passes through, is:

Thus,

Solve for the angle by evaluating the ratios ( I0/I) asked for in parts (a), (b), and (c).
42.  Each of the angles is referenced to the vertical. But the transmitted intensity through the second and third polarizer is referenced to the difference between the angle for that and the previous polarizer. Now,

Thus the final intensity I is given by:

(b)Use the same method as in part (a)
47. Use equation 38.15.