Corinne and I were trying to remember all the issues associated with this example. We were wrestling with why a loop precesses until we remember that it has angular momentum to begin with, which the torque is trying to change ($\tau = dL/dt$). It precesses because the initial angular momentum is in the direction of $\mu$ and $\tau=\Delta L=\mu\times B$.

This year, this activity, combined with the SWBQ on Lorentz Force Law and the mini-lecture on magnetic dipole moment took close to an hour and a half. There were some good conversations, but it would probably go faster to bring the class back together more often, since students seem to be trying to remember formulae. This is harder to do in a large class, but also probably more important in terms of time.

Also, a handout with the diagrams and questions would help cut down on the set-up and could start the conversations earlier.

While the students don't necessarily need to be able to do this calculation to continue for this class, it is important that they can do this kind of a calculation that pulls together pieces of things that they have been learning throughout their intro courses and early paradigms.