# PLz help me in this Corner Reflector Problem

1. Mar 3, 2005

### shaiqbashir

Hi!

Well can u help me in this problem. it is related to a device called Corner Reflector.

" A corner reflector is formed by three mutually perpendicular reflecting surfaces. Show that a ray of light incident upon the corner reflector (striking all three surfaces) is reflected back along a line parallel to the line of incidence.(Hint: Consider the effect of a reflection on the components of a vector describing the direction of the light ray). The Apollo mission placed this type of reflector on the surface of the moon in 1969."

Please help me in this problem, i just donot know how to solve it. i have only two days left for my test. Plz Help

2. Mar 3, 2005

### Jayboy

I believe this coursework problem has been well-answered in the relevant section.

3. Mar 3, 2005

### GCT

"Retroreflection," try finding it through the index of your text.

4. Mar 8, 2005

### Alkatran

Just think about it. The light hits the "X" mirror (which is a 'square' facing down the X axis) and it's x velovity becomes -x. It hits the "Y" and its y velocity becomes -y, it hits the "Z" and its z velocity becomes -z.

So, in the end, it's velocity goes from x,y,z to -x,-y,-z. That velocity is parrallel and opposite the original one!