Particle Physics Questions Part Two (Relativity and Quantum Mechanics)

After a review of the pages linked from the Physics section (including those references contained in the introductory remarks and under the figures), you should be able to answer all of the following questions. Note the key vocabulary words are in italics.

The following questions refer to relativity concepts as used in particle physics.

1. What is meant by relativistic mass? What is meant by rest mass? What did Einstein say about the concept of variable mass? Which mass is the one you find listed on a particle identification chart?

2. What is the primary relationship between energy, momentum and mass? What are the units of energy commonly used in particle physics? How are these units related to the units of momentum and mass?

3. The approximation E = pc is sometimes used for the energy of a particle. For what energies is this expression accurate to within 1%? (Why does the answer to that question depend on the particle under consideration?)

4. Since a photon has 0 rest mass, how can it have non-zero momentum? What relationship defines the energy of a photon?

5. Under what circumstances is is acceptable to ‘ignore’ a particle’s rest mass?

The following questions refer to Quantum Mechanics.

1. What contribution did Max Planck make to the development of quantum mechanics? How did Einstein extend Planck’s breakthrough, in a manner sufficient to merit the Nobel Prize?

2. What role does the Heisenberg Uncertainty Principle play in particle physics? What role did Niels Bohr play in Quantum Mechanics?

3. How did Paul Dirac predict the existence of an anti-electron? How and when was this prediction experimentally verified?

4. In what ways does light exhibit particle behavior? In what ways does light exhibit wavelike behavior? What are the key historic experiments that demonstrate the wave-particle duality of light?