Chapter 34, Problem 5P

You are working for an optical research company during a summer break. Part of the apparatus in one particular experiment is shown in Figure 34.7b. In fact, the experimenter used this text book to set up this part of the experiment, and also used the result in the What If? section to determine the angular change in direction of the light beam:

$\beta =360°-2\varphi$    (1)

The experimenter is constantly grumbling that the measuring device to determine the angle ϕ on the inside of the mirrors is constantly getting in the wav of the light beam and making his life difficult. You quickly draw Figure P34.5 and then say. “Then why don’t you use the measuring device to measure the angle δ outside the mirror, and then your device won’t get in the way of the light?”

The experimenter, who has never thought of this, tries to save face and says to you. “Well, Smarty, then tell me how angle β depends on angle δ!” You provide him the answer quickly.

Figure P34.5