The angle between two plane mirrors that meet at one edge is 45$\degree$.The change in direction of a ray that strikes the first mirror at a 60$\degree$ angle of incidence when that ray reflects from the second mirror is
A)0$\degree$.
B)45$\degree$
C)90$\degree$
D)150$\degree$
E)270$\degree$

Question

Quizplus · Accepted Answer

Since the incident angle at the first mirror is 60F1F1F1S1F1F1F10 and the angle between the mirrors is 45F1F1F1S1F1F1F10, the angle of reflection is also 60F1F1F1S1F1F1F10. Thus, the incident ray reflected off the first mirror as if it came from a virtual source located at a 60F1F1F1S1F1F1F10 angle of incidence to the second mirror.

When the ray from the virtual source strikes the second mirror, it also reflects as if it came from a virtual source located at a 60F1F1F1S1F1F1F10 angle of incidence to the second mirror.

The angle between the ray reflected from the second mirror and the incident ray at the first mirror is equal to the difference between the angle of incidence and the angle of reflection at the second mirror. Using the law of reflection, we find that this angle is:

angle of incidence - angle of reflection = 60F1F1F1S1F1F1F10 - (180F1F1F1S1F1F1F10 - 45F1F1F1S1F1F1F10) = 150F1F1F1S1F1F1F10

Therefore, the answer is D) 150F1F1F1S1F1F1F10.

The Angle Between Two Plane Mirrors That Meet at One °\degree°

The Angle Between Two Plane Mirrors That Meet at One $\degree$