Exercises
Exercise 12A: Exploring Images With a Curved Mirror
Equipment:
concave mirrors with deep curvature
concave mirrors with gentle curvature
convex mirrors
- Obtain a curved mirror from your instructor. If it is silvered on both sides, make sure you’re
working with the concave side, which bends light rays inward. Look at your own face in the
mirror. Now change the distance between your face and the mirror, and see what happens.
Explore the full range of possible distances between your face and the mirror.
In these observations you’ve been changing two variables at once: the distance between the
object (your face) and the mirror, and the distance from the mirror to your eye. In general,
scientific experiments become easier to interpret if we practice isolation of variables, i.e., only
change one variable while keeping all the others constant. In parts 2 and 3 you’ll form an image
of an object that’s not your face, so that you can have independent control of the object distance
and the point of view.
- With the mirror held far away from you, observe the image of something behind you, over
your shoulder. Now bring your eye closer and closer to the mirror. Can you see the image with
your eye very close to the mirror? See if you can explain your observation by drawing a ray
diagram.
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Exercises 845
