Problem 3.5

Please wait for the animation to completely load.

An unknown particle decays into two photons with wavelengths given in the animation.³  You can change the incident speed of the unknown particle.  You can use the pink protractor to measure angles:  click-drag on the gray circles to move and adjust the angle of the protractor. (Angles are given in degrees and wavelengths in nm.)  A relationship you may find useful is hc = 1240 eV·nm.  Restart. 

1. Develop a relationship for the angle the photons leave as a function of β =  v/c.  Verify your relationship using the animation.
2. Find the mass (in MeV/c²) of the unknown particle.  (What is it?)

__________

³Based on Problems 2.37 and 2.39, J. Taylor, C. Zafiratos, and M. Dubson, Modern Physics, Prentice Hall (2004).
 

© 2006 by Prentice-Hall, Inc. A Pearson Company