And, it will be, just not right away. Lat night was the last of the five share sessions for the Phox Valley Physics and Physical Science Share Group. As always, it was awesome professional development. There were some great pedagogical discussions (g = -9.8N/kg was 9.8N/kg, and if it is OK for kids to interchange using N/kg and m/s/s as they see fit), some awesome ideas (using a Hot Wheels Loop-the-Loop to have the students predict the minimum velocity the care needs to make it around); and of course LOADS of freebies to give away as door prizes (gift certificates form Vernier, books from Vernier, goodies from AAPT… the list goes on). I also gave Periscope a test run. It was pretty awesome. One of our former members living on the opposite side of the state could watch the presentations. Periscope even allows me to see how many views there were! I can see a number of applications for it even during class.
OK, now for what I did in class yesterday:
We had the post-activity discussion for the Bulb Boy activity. As I explained in a previous post, I do not use the terms ‘series’ and ‘parallel’ at the beginning of the activity, I prefer to let the activity and the observations create a need for them. Here is how I went about that. I asked the students to prepare WB’s on a given circuit they had set up… just their sketch of what it looked like and the potential values they had measured. We the first group was presenting, I asked a member to trace the path the charge follows. We watched as the member traced FROM the positive terminal (awesome) to the negative, up through a side of the bulb and out the bottom of the bulb. This gave us a chance to talk about conventional current. Each group did that even the ones were there was more than one path (we just used different colors). We also compared the brightness of the bulbs and noticed that the bulbs on cituits with only one path got dimmer as more got were added, but there appeared to be no change in brightness as more bulbs/paths were added to the circuits that already had multiple paths. We even set up the actual circuits to check this and some of the potential difference values.
After this, we summarized everything by creating a list of characteristics we had observed. At the very end of this discussion, I suggested that we give a name to the type of circuit that displays each set of characteristics…. Series and Parallel.
We also agreed that a defined set of symbols might make the circuit drawings easier to follow… enter the schematic circuit symbols!
In this class we practiced using the voltmeter to measure potential differences and we made the simplest possible circuit with one cell, one wore and one bulb (as discussed/referenced in Minds of Our Own). Bulb Boy for this group with the next class meeting.