Cosmology and Quantum Introduction homework

# Cosmology and Quantum Introduction homework - PHYSICS 6...

• Notes
• 1

This preview shows page 1. Sign up to view the full content.

PHYSICS 6 SPRING 2006 HOMEWORK 3 (due Tues. Feb.21) Read : Finish reading the Lightman selection on relativity. Read Feynman, Chapters 1 (to reacquaint yourselves with the atomic/molecular theory of matter) & 4 (read this carefully; energy is fundamental to all we will discuss after E=mc 2 ). Problems: (Problems are to be handed in at the due date.) 1. The charged pion ( π + ) decays into other particles. It has an average decay time of 2.6x10 -8 sec. a. If a π + is travelling in a lab at 0.9999c what is its average decay time? b. How far does it travel before decaying (on the average)? c. The π + turns into three particles (usually muon and 2 neutrinos) when it decays. Suppose the muon is produced along the direction of the π + motion and has a velocity of 0.99c in the π + rest frame. What is the muon velocity in the lab? 2. Judy and Andy are twins. Judy gets on a rocket that goes to a star system 20 light years away from earth (as measured from earth, i.e. Andy's frame of reference). a. She travels at 0.8c. How many years does it take her to reach the star according to
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