Modern Physics

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: PHY251 Homework Set 3 Reading: Chapter 4 Homework: Chapter 4, Questions 3,5,7 Problems 2,8,13,16,32 Hints and Solutions Note: SHOW ALL WORK! Question IV.3 How would you estimate the temperature of a red-hot piece of steel, given that the wavelength of red light is in the neighborhood of 700 nm? What assumption would you have to make for your estimate? Hints: How do you know that the red wavelength is a maximum, and not a tail of the distribution in the visible part of the spectrum? Solution: If it were the tail of a shorter wavelength distribution, the color would be more yellow-blue; it could, however, be the high-end tail of the distribution, with a maximum at the near infrared; the radiation would be weaker ("dull-red") and the temperature would be somewhat less. Assuming we indeed see the maximum at λ = 700 nm, the temperature is simply derived from: λ max · T = 2.9×10-3 m·K; T = 2.9×10-3 m·K / 700 nm = 4.1×10 3 K. Question IV.5 Suppose you have a source that emits a beam of light at some frequency f that impinges on a metal plate. What happens to the energy of the photoelectrons that are emitted when you are moving the source closer to the plate? Hints: What happens to the frequency when the source approaches the observer (electron)? Solution: The Doppler effect will make the photon's frequency to the electrons a bit higher, and therefore more energetic. The photoelectrons are thus slightly more energetic on average....
View Full Document

This homework help was uploaded on 02/05/2008 for the course PHY 251 taught by Professor Rijssenbeek during the Spring '01 term at SUNY Stony Brook.

Page1 / 3

solutions 03 - PHY251 Homework Set 3 Reading Chapter 4...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online