relevant background: These questions are about "homopolar" motor , here's a video of it working at this link https://thumbs.gfycat.com/ArtisticRealDragonfly-size_restricted.gif .

Background for question: The "body" of the battery is actually a steel cylinder filled with chemical goodness that generates ~ 1.5 V DC. It was our guess that the wire moves because there is a current flowing through the wire and that the current is interacting with the magnetic field from the little magnet which is "channeled" by the thin steel shell of the battery body.

Question 2:

a.) So it looks like there could be several different things keeping the wire from moving quickly. Here's the list we came up with: Friction at the contact points - how might we test for this? What if you have a conductive metal disc the same size as the batteries? Can you sketch a picture of how you might investigate this? Your answer:

b.) Air drag - how might we investigate this?Remember that air drag increases with the square of speed. Your answer: c.) Now we're getting down to the "motory" part... You learned about forces generated by currents in magnetic fields. For this goofy motor to rotate we need an "unbalanced torque". Referring to the goofy motor with a coil of wire, where do you think the force is generated?

Your answer:

d.)It also looks like this wire moving in a magnetic field might induce a voltage down the wire. What do you think about that? What might this be called? Your answer:

e.)Thinking about all of this, do you have any guesses about how you can maximize the torque on the wire? Your answer: Go ahead and make a sketch if you can...