The two figures below show one of the authors’ reflections in a (concave) make-up mirror. Use the ideas we’ve developed to explain what one sees in make-up mirrors.
Looking in a make-up mirror from far away.
Looking in a make-up mirror from up close.
Make-up mirrors are concave spherical mirrors.
The figure above shows a two-dimensional cross section of a concave spherical make-up mirror whose radius is ten inches. A person is looking at his or her reflection in the mirror from very close (three inches from) the mirror. Use the ideas we’ve developed so far to find the apparent position of each of the person’s two eyes as seen in the mirror. Explain how this mirror “magnifies” the person’s image.
After you’ve done the problem above look at a person’s image when the person is far away from the mirror.
For instructors only after you have completed the scene click on SPOILER ALERT.
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