Physlet Illustration: Reflection in a Concave Mirror

 

 

In this simulation, a 0.5-cm high object is placed in front of a concave mirror of focal length  f = 0.5 cm. The focal points are indicated both in front of and behind the mirror. How and where is the image formed? What are the characteristics of the image?

Hints:

  1. Drag the object until it is far from the mirror, and study the image produced.
  2. Verify that the law of refection governs the behavior of each principal light ray that strikes the mirror's surface.
  3. Do the rays that leave the top of the object, traveling in different directions and reflecting off the mirror, ever come together again?
  4. Do those rays, having reflected from the mirror, appear to emanate from the same point behind the mirror?
  5. Is this, then, a real or a virtual image?
  6. Fix the object at some distance, do, in front of the mirror. (The mirror itself is located at x = 2.0 cm.) What is the corresponding image distance, di? (Remember that di is negative for images behind a mirror.)
  7. Verify that the mirror equation is obeyed.
  8. How does the image's height compare to the object's height? Is the image upright or inverted?
  9. Do these results agree with the calculated value of the magnification?
  10. Now, place the object very close to the mirror, and repeat all of these steps.

Reference

See Walker, Section 26-4


Illustration written by Steve Mellema