# Thread: rayof light with mirror, find angle reflected.

1. ## rayof light with mirror, find angle reflected.

A ray of light strikes a plane mirror at a 45° angle of incidence. The mirror is then rotated by = 15° into the position shown in red in the drawing, while the incident ray is kept fixed.

image: http://img530.imageshack.us/img530/8505/p2508altvy8.gif

(a) Through what angle does the reflected ray rotate?
in degrees

(b) What is the answer to part (a) if the angle of incidence is 60° instead of 45°?
in degrees

anyone who can go through this one please.

2. Ok, well this looks like year 11 physics to me...

Incidence = Reflected...

so if you rotate the mirror 15 degrees you are essentially rotating the ray 15 degrees into the mirror…

so at 45degrees … rotate it 15 degrees towards the mirror instead of moving the mirror to the ray… and you should have 30 degree incidence ray and a 30 degree reflected ray … ?

Is it this simple or have I misunderstood the question..

if you want to say … 15 degrees to the horizontal but I doubt that was the question….

Sorry if I sound convoluted?

3. Hey, you are correct it isn't that hard a problem evidently. I thought I was going to have to use trig, from glance it looked like the problem was set up that way. Upon closer observation though your explanation is clear enough.

Thanks alot for the help.