An image is magnified by 2.50, concave mirror confusion wee

AI Thread Summary
A concave shaving mirror with a radius of curvature of 37.0 cm produces an upright image that is 2.50 times the size of the object. The discussion focuses on calculating the object distance from the mirror without initially knowing the image distance. Participants suggest using simultaneous equations to relate the object distance (do) and image distance (di). By substituting these values into the lens equation, the correct object distance of 11.1 cm is determined. This approach effectively resolves the confusion surrounding the problem.
mr_coffee
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Hello everyone< i think I'm on the right track but now I'm stuck.
Here is the problem:
A concave shaving mirror has a radius of curvature of 37.0 cm. It is positioned so that the (upright) image of a man's face is 2.50 times the size of the face. How far is the mirror from the face?

Here is my work and drawing:
http://suprfile.com/src/1/6mwvik/lastscan.jpg I'm conufsed on how I'm suppose to find the object distance if I'm not giving the image distance.
 
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Simultaneous equations. You have both of them. Two unkowns, di and do.
 
Chi Meson said:
Simultaneous equations. You have both of them. Two unkowns, di and do.
like he said
instead of using the hi-ho (:smile:) relation find a relation between di and do.

sub into your lens equation and you're all set.
 
Awesome thanks a lot guys worked great!
11.1cm for object distance, o yes!
 
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