Bertozzi's Experiment

• What is the formula for kinetic energy gained by a charged particle?

  qV = Ek
• What was the aim of Bertozzi's experiment?

  To compare kinetic energy and speed predictions
• How did Bertozzi accelerate electrons?

  Using a strong electric field
• What was used to measure the speed of electrons?

  Distance divided by time
• What happens to electrons after leaving the electric field?

  They travel at constant speed
• How did Bertozzi measure the time interval in the experiment?

  Using an oscilloscope with two signals
• What were the results of Bertozzi's experiment regarding kinetic energy and speed?

  • Results agreed with relativistic predictions
  • Showed electrons cannot exceed the speed of light
  • Data disagreed with Newtonian predictions

  
• How did Bertozzi verify the kinetic energy of electrons?

  By measuring temperature change of the target
• What equation did Bertozzi's team use to measure energy change?

  ΔE = mcΔθ
• What does the total charge transferred to the target help calculate?

  The number of electrons hitting the target
• How is the total thermal energy gained by the plate calculated?

  ΔE = mcΔθ
• How do you calculate the number of electrons incident on the aluminium plate?

  n = Q/e
• How do you convert kinetic energy per electron into mega-electronvolts?

  Ek = $\frac{1.0475 \times 10^{-12}}{1.60 \times 10^{-19}}$
• What is the final kinetic energy per electron in MeV?

  6.55 MeV
• What should you expect regarding methods of determining kinetic energy in exams?

  • Be familiar with thermal energy equation
  • Understand work done by electric field