- #1
Niki4444
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Homework Statement
the figure shows a combination of two identical lenses. There is a 2cm tall object that is 36 cm away from the first lens (f=9 cm). The second lens is 15 cm away from the first lens. It also has a focal length of 9 cm. So, the first question was "find the position of the final image of the 2 cm tall object". I've solved that one, using 1/f=1/s+1/s' for each lens, making sure to use the "image" from the first lens as the "object" for the second lens. The next question is "find the size of the final image of the 2 cm tall object".
Homework Equations
I thought I could use h'/h=s'/s, although that didn't seem to work out.
I already used 1/f=1/s+1/s'
The Attempt at a Solution
My attempt was to use h'/h=s'/s. I thought I would solve for h' (height of image).
I tried to do this in a 2 step process
a. used original object size & lens #1 h'/2=12/36
b. used image from 1st lens as "object" for second lens h'/0.67=45/3
c. got 1.01 cm which is incorrect.
Any helpful thoughts to move me in the right direction would be hugely appreciated.
Thanks in advance.