Conceptual Physics (12th Edition)

Published by Addison-Wesley
ISBN 10: 0321909100
ISBN 13: 978-0-32190-910-7

Chapter 30 - Think and Explain - Page 579-581: 34


We will cut the photon energy in half.

Work Step by Step

From our study of wave motion, page 362, we know that $f = \frac{c}{\lambda}$, where c is the speed of light. The photon frequency is inversely proportional to its wavelength. Doubling the wavelength means halving the frequency. For photons, E = hf, where E is the energy, h is Planck's constant, and f is the photon's vibrational frequency. Half the frequency means half the energy per photon. This is discussed on page 564. In summary, twice the wavelength means half the frequency, which means one-half the energy per photon.
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.