Physics Help Forum Concave spherical mirror in a car headlamp

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 Feb 14th 2011, 11:14 AM #1 Junior Member   Join Date: Feb 2011 Posts: 5 Concave spherical mirror in a car headlamp I'm given only the object distance from the mirror. How would I find the focal length?
Feb 14th 2011, 12:12 PM   #2

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 Originally Posted by Tesoro72 I'm given only the object distance from the mirror. How would I find the focal length?
Have you tried looking this up on your text? Or on-line? There is a simple formula based on the radius of the mirror.

-Dan
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 Feb 17th 2011, 01:52 PM #3 Junior Member   Join Date: Feb 2011 Posts: 5 I couldn't find a simple equation in the book, but my teacher reviewed the assignment
Feb 17th 2011, 02:29 PM   #4

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 Originally Posted by Tesoro72 I couldn't find a simple equation in the book, but my teacher reviewed the assignment
For the record f = -R/2 where R is the radius of the mirror.

-Dan
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 Tags car, concave, headlamp, mirror, spherical