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a person views his face in a 20- cm focal length concave mirror. where should his face be in order to form an upright image that is magnified by a factor of 1.5?

User Ryan Cook
by
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1 Answer

4 votes

M = -di/do

We can solve this equation for di:

di = -M × do

Substituting the given values:

di = -(1.5) × do = -1.5do

Now we can substitute both equations into the mirror equation and solve for do:

1/(-20 cm) = 1/do + 1/(-1.5do)

-0.05 = 1/do - 2/3do

-0.05 = (1 - 2/3)/do

-0.05 = 1/3do

do = -3/(0.05) = -60 cm

The negative sign indicates that the object (person's face) is located in front of the mirror, which is consistent with the fact that it is a concave mirror. Therefore, the person's face should be located 60 cm in front of the concave mirror in order to form an upright image that is magnified by a factor of 1.5.

User Luke Wage
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8.1k points