This week in Physics 100, we began talking about mechanical energy. For our first class this week, I went back to what I feel is one of the canonical examples of mechanical energy conservation: the roller coaster.
This is something I explicitly remember as being the topic of energy problems in my high school physics class. In fact, in my high school, the physics classes typically went on a field trip to the amusement park. Unfortunately, the particular class I was in did not get to go on this field trip. In the Physics 100 lecture, I did not get the feeling that this image provoked much from the students; perhaps it was too generic?
Before the second class of the week, the instructor and I talked about using something in the pop culture domain in order to better capture the students attention. I suggested that the recent Red Bull Stratos event could be relevant and interesting for the students. (This event is also used in the motivation for a lab about terminal velocity later in the term.) The instructor found the following YouTube clip:
In some of the previous lectures, when the instructor showed videos, I noticed that the class appeared to focus more than during ‘normal’ lecture activities. For this pre-class video, I noticed more students looking at the video than I did students looking at the images in previous classes.
In addition to just being neat, this video has some interesting graphs along the right side. As a physicist, I automatically try to connect the dots between altitude, airspeed, and g-force. These are related to concepts we talked about in lecture, including mechanical energy, apparent weight, air drag, and terminal velocity. Our hope was that some students might try to connect the dots also. Indeed, in his brief introduction using the video, the instructor suggested that students do exactly that. However, we did not explicitly probe the students for thoughts, so it may be that this suggestion was lost on most students as just another ‘physics exercise’. One indication that this video may have been more successful than previous images was that during the pre-class time, the instructor and I did interact with one student who was trying to understand the graphs.
In summary, it appeared to me that the video attracted more attention than any previous image. This may have been due to it being a video, it having a recognizable brand name attached to it, or perhaps some other explanation. As emphasized by Peter Newbury (see comment on this post), one of the most important uses of the pre-class overhead is to connect to students’ previous experiences and allow them to bring previous knowledge into the classroom. It is not clear that we have had any success in this regard yet, but I hope to have more to say about that in future weeks.