What kind of lens is behind the orange curtain?

Horizontal position of the object
-200 cm -25 cm
Check here to show multiple rays

Inspired by a 2002 article in The Physics Teacher by Melissa Dancy, Wolfgang Christian, and Mario Belloni.

Test your familiarity with lenses. You can find the focal length of a converging or diverging lens by calculating it, but see if you can get to the point where you can find it without doing a calculation.

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This work by Andrew Duffy is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Posted 6-15-2020. Authored by Andrew Duffy.

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