This was not really a full day, it was an early release because of Parent Teacher Conferences. The students continued to gather data for the energy experiment. The class was split in two, with half doing a kinetic energy experiment, and the other half doing a gravitational experiment.
We had just enough time to work through a sample N2L problem. We used the WDSS mounted on a cart and a motion detector. The problem was to determine the velocity of the cart 1.5 seconds after it was released from my hand. The WDSS provided the (net) tension force, so the students had to first determine the acceleration of the cart (verified with the motion detector) with N2L, then the velocity at t = 1.5s (again verified with the motion detector).