Celsius 27316 K 1 cal 419 J 2 Problem 1 A star goes supernova 1000 light years

# Celsius 27316 k 1 cal 419 j 2 problem 1 a star goes

This preview shows page 7 - 10 out of 10 pages.

Celsius = 273.16 K 1 cal = 4.19 J 2
Problem 1:A star goes supernova 1000 light years away. Neutrinos of mass 0.1 eV/c2immediately streamtoward the Earth with an energy of 1 GeV. One hour later, light from the explosion escapesthe dense cloud of debris surrounding the former star and travels toward Earth.Shouldastronomers point their telescopes toward the star after seeing a neutrino burst, or turn ontheir neutrino detectors after seeing a light burst? I.e., do the neutrinos or photons arrive atEarth last? How long does it take for the latter to arrive?Problem 2:Last year a new particle that could be the Higgs boson was found at the Large Hadron Colliderat CERN. The particle was observed through its decay into two photons, and it has a massof 125 GeV/c2.(a) If the “Higgs” was produced at rest, what was the minimum photon energy observed?(b) If the particle is a Higgs boson, it should decay tobquarks of mass 5 GeV/c2. For aHiggs boson produced at rest, what would be the maximum speedβof thebquark?(c) For a Higgs boson produced with 40 GeV/c of momentum, what is the maximum energyexpected for a photon from the Higgs decay? 3
Problem 3:A square loop of wire (sidea) lies on a table, a distancesfrom a very long straight wire,which carries a currentI, as shown in the figure.(a) Find the flux ofBthrough the loop.(b) If someone pulls the loop directly away from the wire, at speedv, what emf is generated?In what direction (clockwise or counterclockwise) does the current flow?(c) What if the loop is pulled to therightat speedv, instead of away? Problem 4:Two perfect dipolesp1andp2are a distancerapart and oriented as shown in the figureabove. Find the torque (about its own center) onp1due top2. Problem 5:A cubical box (sides of lengtha) consists of five metal plates, which are welded together andgrounded. The top is made of a separate sheet of metal, insulated from the others, and heldat a constant potentialV0. Find the potential inside the box.aaayxzVo 4

#### You've reached the end of your free preview.

Want to read all 10 pages?

• Spring '08
• Laurent-Muehleisen
• Physics, Mass, Atomic mass unit