# Day 5: Shopping Carts and Forces

Physics: Today was the second day of inertia and going over the homework questions. We watched the shopping cart video, the motorcycle table cloth video, and the Mythbusters treatment of the motorcycle table cloth video.  I made a lot of call-backs to the station labs they did yesterday, which was super valuable. After that  was getting them set up for the review tomorrow for the exam on Thursday. I’m still following my colleague lock-step and using his exams, so I will need to spend some time tonight going over the test carefully and make sure I have covered all the topics appropriately.

Honors Physics: Our first lab section. This was probably the last structured lab I have ever tried, but they were working the entire time and probably could have continued working for another hour if I would have let them. I picked some things in lab (a pull-back tractor, an indoor soccer ball thing, a baseball on a ramp) and asked the students to convince themselves and each other whether or not the acceleration of the object is constant (the tractor after pull back, the soccer ball after being kicked, and the baseball rolling down the ramp). They each tried different ways to measure time and distance, some of which worked ok and some did one. The baseball group graphed their position vs time results and used a best-fit line, but they forced it to be a second degree polynomial, which automatically causes constant acceleration. Another group just kinda kicked or shoved the indoor soccer ball, but there was no consistency. Tomorrow we are going to debrief different ways of approaching taking measurements and talk about how “human error” is not an acceptable option for “where did your errors come from?”

AP Physics: My first class needed a lot of extra support on vectors, so we spent a lot of time going over the homework. My second class did not, so we moved on to talk about balanced and unbalanced forces and start practicing how to draw free body diagrams. Tomorrow I’ll try find more practice problems for the second class to do, but I’m finding limitations in terms of not having done Newton’s Laws or formal force notation. I’ll see how this goes in terms of letting them do whatever now and getting more picky in the future and see if they are able to make the change effectively.