This class was spent WB’ing four of the six projectile motion problems they had been working on. I choose one of them; a goalless problems as described by Kelly O’Shea here. I like these because they can get us away from specific types of problems and pose some really interesting ones. I usually use one of them as some extra practice during class or as some at home practice.
We are nearing the end of the constant velocity unit, so it is time for a Challenge lab. The one I choose this year was to race the buggies side-by-side but the need to cross the finish line at the same instant. Each group can use two buggies but only one at a time. There get a slow one (one cell with a slug in place of the other cell) and a fast one. They can determine the velocity using any of the methods we have used so far… measuring positions and times, or video analysis, or even with the motion detector. The students use the velocities to determine the starting positions.