Today we started the Central Force Particle Model with a conceptual paradigm lab. I have never tried bowling balls and mallets before, but I picked up some cheap mallets over the winter break and found four bowling balls that we had laying around. The activity was a good review of unbalanced forces. It was reassuring to see students converge on the concept that a force directed toward the center of a circle is required to keep the bowling ball moving in a circle. We worked in the hallway instead of on a basketball court. We’re not suppose to put tape on the waxed floors; so, we used a hula hoop as the indicator for the circle. The lab went well, and I’ll need to find a couple more bowling balls for next year!