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An electron is shot through four regions of constant magnetic field (position is given in centimeters and time is given in seconds). Restart.

1. In which direction is the magnetic field in each region?
2. Rank the magnitude of the magnetic fields of the four regions, from smallest to greatest.
3. How would the path change if we inverted the direction of the magnetic field in every region? Draw the new path of the electron.
4. If you wanted to ensure that the particle did not enter Region II, would you increase or decrease the speed of the electron entering Region I? Give a mathematical proof of your answer.

Problem authored by Dwain Desbien and Melissa Dancy.