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tiger1
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[SOLVED] Focal length of a mirror
A 2.0-cm-tall object is placed in front of a mirror. A 1.0-cm-tall upright image is formed behind the mirror, 150 cm from the object.
What is the focal length of the mirror?
1/f=1/s+1/s'
m=h'/h
m=-s'/s
.5=-s'/s
s+s' = 1.5m
Combining those 2 equations, I get:
s'=3
s=-1.5
1/f=(1/-1.5)+(1/3)
f=3m
When I calculate it the focal length, f, it comes out to 3m, which is obviously way too big.
Homework Statement
A 2.0-cm-tall object is placed in front of a mirror. A 1.0-cm-tall upright image is formed behind the mirror, 150 cm from the object.
What is the focal length of the mirror?
Homework Equations
1/f=1/s+1/s'
m=h'/h
m=-s'/s
The Attempt at a Solution
.5=-s'/s
s+s' = 1.5m
Combining those 2 equations, I get:
s'=3
s=-1.5
1/f=(1/-1.5)+(1/3)
f=3m
When I calculate it the focal length, f, it comes out to 3m, which is obviously way too big.
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