Day 10: Cart Launch Lab AnalysisPosted: September 10, 2013
Today we analyzed the data we gathered for the cart launch lab. It’s pretty much the same as the buggy lab (drop pennies or tape at constant time intervals as a CV buggy rolls along, gather position vs. time data), but instead we launch a dynamics cart on a horizontal track and drop digital pennies. I do this this lab after a modified version of WS 1 from the standard modeling materials (stolen from Kelly), and I really like the placement of the lab here for four reasons.
- It introduces video analysis as the same process as the buggy lab, so they understand what video analysis is doing (though we still have to have a conversation about how it gets velocity information)
- It introduces velocity graphs easily and somewhat authentically.
- It is a good way to induce that the area under a v vs. t graph is displacement
- It starts the process of breaking ##CVPM. Most of the X velocity vs. time graphs are not horizontal, though students recognize they should be. Then they notice the position graphs aren’t perfectly linear, they seem to curve a bit. We will do more with CV after this, but I like to get them thinking about how our models aren’t perfect for all situations.