Chapter 22, Problem 1PCE

Predict/Explain Proton 1 moves with a speed v from the east coast to the west coast in the continental United States; proton 2 moves with the same speed from the southern United States toward Canada. (a) Is the magnitude of the magnetic force experienced by proton 2 greater than, less than, or equal to the force experienced by proton 1? (b) Choose the best explanation from among the following:

1. I.                    The protons experience the same force because the magnetic field is the same and their speeds are the same.
2. II.                  Proton 1 experiences the greater force because it moves at right angles to the magnetic field.
3. III.               Proton 2 experiences the greater force because it moves in the same direction as the magnetic field.