Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (3rd Edition)

Published by Pearson
ISBN 10: 0321740904
ISBN 13: 978-0-32174-090-8

Chapter 24 - Optical Instruments - Exercises and Problems - Page 712: 1

Answer

See the detailed answer below.

Work Step by Step

$$\color{blue}{\bf [a]}$$ We can use any software calculator to get the final image object, as seen below. $$\color{blue}{\bf [b]}$$ We need to find the position of the first image of the first lens of 40 cm focal length. Using thin lens formula, $$\dfrac{1}{s_1}+\dfrac{1}{s_1'}=\dfrac{1}{f_1}$$ Hence, $$s_1'=\left[\dfrac{1}{f_1}-\dfrac{1}{s_1}\right]^{-1}$$ Plugging the known; $$s_1'=\left[\dfrac{1}{40}-\dfrac{1}{15}\right]^{-1}=\bf -24\;\rm cm$$ which is exactly as seen in the figure below. The height of the first image is given by $$m=\dfrac{h_1'}{h}=\dfrac{-s_1'}{s_1}$$ Hence, $$h_1'=\dfrac{-hs_1'}{s_1}=\dfrac{-(2)(-24)}{15}=\bf 3.2\;\rm cm$$ This image is the object of the second lens of 20 cm focal length. This image is at a distance of $s_2=24+10=\bf 34$ cm from this lens Hence, $$s_2'=\left[\dfrac{1}{f_2}-\dfrac{1}{s_2}\right]^{-1}$$ Plugging the known; $$s_2'=\left[\dfrac{1}{20}-\dfrac{1}{34}\right]^{-1}$$ $$s_2'=\color{red}{\bf 48.6}\;\rm cm$$ which is exactly as seen in the figure below as well. The height of the second image is given by And as we see the two heights of the two images are matching those that are on the graph.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.