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What is the magnification of an astronomical telescope whose objective lens has a focal length of 82 cm, and whose eyepiece has a focal length of 2.8 cm? What is the overall length of the telescope when adjusted for a relaxed eye?

Giancoli, Douglas C., Physics: Principles with Applications, 7th Ed., ©2014. Reprinted by permission of Pearson Education Inc., New York.
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Quick Answer: 

-29X, 85 cm

Giancoli 7th Edition, Chapter 25, Problem 31


Chapter 25, Problem 31 is solved.

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Just wanted to let you know that there is a typo. For the value of magnification, the quick answer is "-2.9X" but the answer from the video is "-29X." Thank you for your awesome video!

Hi Theovilous, thank you very much for spotting that! I've corrected it. Thanks also for letting me know the videos are helping with your studies. Keep it up!