CATAGORY: Light
 QUESTION: Suppose a mirrored surface has a cross section in the shape of
one branch of a hyperbola. if a ray of light is headed toward the
hyperbola's focus behind the mirror, the mirror will reflect the light
through the other focus, as shown at the right. Draw a similar diagram for
each of the following situations.
    a.)A mirrored surface has a cross section in the shape of a parabola.
If a ray of light parallel to the parabola's axis of symmetry strikes the
mirror, the mirror will f\reflect the light through the parabola's focus.
    b.)A mirrored surface has a cross section in the shape of one end of
an
ellipse. If a ray of light passes through the focus closest to the mirror
and strikes the mirror, the mirror will reflect the light through the
other
focus.

Back to catalog.

---

              
               |<------<-------<----------<-------
              | \              Parallel incomming ray
(a)          |   \
             |    \
            |      \
            |       \             optical axis
       -----|--------X---------------------------------- 
            |    focal point
            |
             |
             |
              |
               | 
           Parabolic mirror   
           
           
           
                    +   (+ + + = section of eliptical mirror)
(b)             +  / \
              +   /   \
             +   /     \
            +   /       \
            +  /         \
          --+--x----------x---
            +  focal     focal 
            +  point     point
             + (close)   (far)
               +
                 +
                     +