How Does Light Reflect Off Two Mirrors Set at a 60 Degree Angle?

[Jacob87411]

Two mirrors are connected and form a 60 degre angle. A ray of light comes in at 65 degrees above the parallel. What direction does the ray leave at?

Well its going to reflect to the second mirror at 65 degrees because the angle it comes in at is the angle it leaves at. However does it leave the second mirror at 65 degrees also or different. I assume it has something to do with the 60 degrees the mirrors are at.

 

[Doc Al]

Draw yourself a careful picture of the two mirrors and the incident light. Then apply the law of reflection and see what happens.

 

[thepatientmental]

The ray of light will leave the second mirror at an angle of 70 degrees. This can be calculated by using the law of reflection, which states that the angle of incidence is equal to the angle of reflection. Since the ray of light came in at 65 degrees above the parallel, it will reflect at 65 degrees below the parallel, making the angle of incidence 25 degrees (60 degrees - 25 degrees = 35 degrees). The angle of reflection will also be 25 degrees, resulting in a total angle of 70 degrees. This follows the principle of the angle of incident problem - that the angle of incidence and angle of reflection are equal and opposite.