Actually what I meant was a photogate similar to the CPO pendulum system (http://freyscientific.com/stem-solutions/cpo-science/support/past-programs/pendulum). This photogate measures the amount of time the plumb bob occludes the timer laser as it passes through the photogate thereby allowing you to calculate the bob’s average speed at the point of the photogate, if you know the diameter or width of the bob. With your system you could place the photogate at any point along the arc of the pendulum allowing you to calculate the speed of the bob at many different points. You could also add a zero line which passes through the center of the bob at its lowest or zero point. With these additions students could apply the mechanical energy theorem and calculate the changes in both PE and KE at many points of the arc. This would be reinforced by your current energy graph. Also you might add the energy value, joules, to the energy graph. These are just some thoughts I had while trying to making the interactive more qualitative.
oliver-phet
commented
6 years ago