With both levels (Advanced and General) I opened up an inertia balance graph I had created in Logger Pro. I used to demonstrate a few of the other awesome features of Logger Pro. The first was the Interpolation feature (under the Analyze menu). Earlier in the week we did the Inertia Balance challenge where the students used their hand graphs to predict an unknown mass (a king-size candy bar). The students immediately saw how much easier and more accurate this method was compared to the hand graph. Another feature I showed them was a calculated column. My original graph had 3 columns; mass added, total time, and period. The period was the calculated column. I showed the classes this as a preview to working with nonlinear graphs, setting the table for the process of linearization. This lead us into a pre-lab discussion for an experiment that will give us a non-linear graph.
The Advanced classes are investigating the factors affecting the period of a pendulum. It was interesting to see the discussion among the class and lab groups about whether or not the amplitude affects the period. I really did not do much other that suggest there is a really easy and quick way to see if it really matters… most groups decided to do a quick check with the equipment. I did encourage the groups to stay away from really big amplitudes.
The General classes are investigating a mass on a spring. They are just looking at period as a function of mass. The spring itself as a factor that affects the period did come up in the pre-lab discussion. We agreed to see if it is a factor by comparing the slope of the linear graph when we WB it. I like this as the second experiment for the general classes because it essentially the same experiment as the inertia balance (period vs. mass), so there is no new procedure for the students to write, they are able to see that the data table is the same, gathering the data is essentially the same, BUT they will end up with a non-linear graph to work with.