{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Homework 2 Solution

# Homework 2 Solution - PHYS 3022 Introduction to Cosmology...

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

PHYS 3022 Introduction to Cosmology Spring 2014 Homework Solutions Week 2 Problem 1 Note: be careful not to make the mistake λ peak = c/ ν peak . The distribution of black body radiation (Planck’s Law) as a function of frequency has a di ff erent shape than the distri- bution as a function of wavelength. To find the peak of each function (Planck equation for frequency or wavelength), you must apply calculus of variation (take derivative and set to 0) to the Planck equation for each function. This question asks you to find the peak intensity wavelength for the CMB. Thus, in answering (a) and (b), using the wavelength form of Wien’s Law: λ m hc kT × 0 . 201405 , then the result is 1 . 1mm for the CMB and 5 . 0 × 10 3 ˚ A for the Sun. For (a) and (b), if you used the frequency form of Wien’s Law, and then erroneously converted to wavelength via λν = c you would see that in fact you would get di ff erent answers than above. h ν m kT 2 . 822 and using λ m = c ν m , then the result is 1 . 9mm for the CMB and 8 . 8 × 10 3 ˚ A for the Sun.

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern