We finished up our balanced torque problem today, but today was mostly spent how to describe rotational motion. An object that isn't spinning is easy to describe, but how do we describe a bicycle wheel that's spinning at a constant rate? Students in groups tried to find a number that would describe the spinning rate. We came up with two different numbers: the velocity of the edge of the bicycle wheel and the revolutions per minute (rpm) of the bicycle wheel. We talked about the strengths and weaknesses of each approach and came up with an even better measure of the velocity of the wheel.
We then looked at a setup in the picture above; we came up with predictions of what the angular position-time and angular velocity-time graphs would look like. We weren't sure if they were right, so we went into lab to collect data. Our angular position-time graphs looked just like parabolas, so I guess the angular acceleration is constant. I wonder how angular acceleration is related to torque?