A lens and a convex mirror problem

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zimo
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Homework Statement


A body is positioned 40 cm from the left of a lens (f=30) and the lens is positioned 100cm left of a convex mirror (|R|=60), where will be the image and what type and magnitude will it have?


Homework Equations


1/u + 1/v = 1/f


The Attempt at a Solution


I tried to calculate the image after the lens - and got v = 120 cm.

Now, I don't know how to interpret the answer.
Can anyone help me out on this?

Thanks
 
Attachments
  • Optics diagram on a horizontal axis: object O with upright arrow O' 40 to the left of a converging lens marked |f| = 30, which sits 100 to the left of a concave-facing mirror marked |R| = 60, with the distances 40 and f = 100 labelled below.
    problem_3_10.png
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The convex mirror interrupt the rays to form the real image.
So (120 - 100) = 20 cm becomes the virtual object distance for the convex mirror. Now proceed.
 
You can consider the mirror concave, and find the image distance that way, or you take it convex and use negative object distance.

ehild
 
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