Using Kaufmann and Bucherer's Data to Relate E, p & m
In 1901, W. Kaufmann did an experiment to investigate the relationship between velocity and mass for electrons in the 0.7MeV to 1.6 MeV energy range (W. Kaufmann, Gottingen Nach. 2, 143; 1901). Later, A. H. Bucherer did a similar experiment which included lower energy electrons (A. H. Bucherer, Ann. d. Phys. 28, 513; 1909).
In each case, deflection of electrons by a magnetic field yields momentum information while deflection by an electric field gives energy information. Thus, we can adapt the data of Kaufmann and Bucherer to show the relationship between E and p. We include simulated data for energies close to the electron rest energy to make your graph clearer.
To view and analyze the data, go to the data page.
- How can you use graphical analysis to discern a relationship between E and p using this data?
- What sort of function is a graph of E vs. p? of E2 vs. p2?
- What is E when p = 0? What does this indicate?
- What does the relationship between E and p look like when E is much greater than the rest energy?
- Can you infer a mathematical relationship between E, p, and m?