Chapter 23, Problem 3P

Two plane mirrors meet at a 135⁰ angle, Fig. 23-52. If light rays strike one mirror at 34⁰ as shown, at what angle φ do they leave the second mirror?

To determine

What angle $\varphi$ do they leave the second mirror?

Answer to Problem 3P

Solution:

$\varphi ={11}^{°}$

Explanation of Solution

Given info:

Angle between mirrors ${135}^{°}$

$\theta ={34}^{°}$

Formula used:

The law of reflection can be applied.

Calculation:

At the first reflection the angle $\theta$ and at the second reflection the angle is $\varphi$

Considering the triangle formed by the mirror and the first reflected ray.

$\begin{array}{l}{\varphi }^{}+\theta +{135}^{°}={180}^{°}\\ or\\ \varphi ={180}^{°}-{34}^{°}+{135}^{°}\\ \varphi ={11}^{°}\end{array}$