Rather than a typical lab practicum like we do for most units, we did an engineering design lab instead. Casey Rutherford shared a great lab last year where students designed, built, tested, redesigned, and rebuilt bumpers to minimize the force experienced when a cart crashes into a barrier at the end of an elevated track. Students were very engaged in the lab and quite the competitive atmosphere among groups developed. Here is the design that performed the best:
Here is an example measurement (red is without the bumper; blue, with):
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