Causality

As mentioned in the prior post, some of the students' behavior is disrespectful, absurd, destructive and a whole list of other things I'd rather not say. To provide some examples;

• Tardiness -Today less than half of the class returned from lunch on time. The usual problem was compounded by the lack of bells (the MME is still going on), but even on a regular day up to 1/3 of the class can be late. Even worse, they're late not because they couldn't get to class on time but because they loiter just outside the door and refuse to come to class when told to do so.
• Texting -It happens all the time. For some it seems like an outlet when they find the material too difficult or confusing, others just a way to pass time. In either case, most will respond when told to put away their phones and then wait several minutes to remove them again. I've had several tell me to wait until they finish their text, and others that will start texting after asking me to explain a problem. On a brief side note; why students play back music on their phones as they walk around is entirely beyond me.
• Insubordination - The other day a student was given a ruler to use for graphing on a quiz. Throughout the quiz he talked continuously despite being told not to, and furthermore decided that insulting other students and making a wide array of noises was a great idea. After the quiz he took to spinning around his ruler and throwing it at which point Molly asked that I take it away. I told him to hand me the ruler and he started to play the game where he pulled it away at the last instant. In the background the teacher is trying to continue instruction while scolding him, and I'm getting awfully close to telling him how I really felt about his antics. I think Molly has given up on sending students out in all but the worse cases as she had removed the student several times during the week to no effect. It's awful to feel completely impotent as an instructor.

In each case, the consequences are either mild or inconsistent which (I think) give the students the impression that the teachers have no authority. My understanding is that our class is not an exception in this respect either. I rarely had kind words for my teachers in high school, but I was damn sure never to say them in any situation where the teacher in question could hear me. At YHS it's not uncommon to hear a few students each day muttering obscenities at me behind my back. My father would say that I have a bleeding heart for the number of times I've tried to help students that just immediately prior insulted me, I'm all for second chances. However, at this point I've begun to wonder if there's some sense in KIPP's military-style discipline. Even if the school adopted stringent and uniform policies that were enforced equally by each teacher, the necessary momentum to change the attitude of high schoolers has got to be enormous.

I don't want to be so glum though. There are a number of students that are respectful, but they can be hard to notice with everything else going on and they're certainly not the majority. I was hesitant to bring up the subject because I harbored some belief that an instructor could be so compelling that they shouldn't have to resort to anything so crude as punishment. As the behavioral issues have continued through about 7 months of classes, it is apparent that something fundamental should change. The trouble is in determining what that is.

Passer Rating

Yesterday I finished grading the worksheets I had handed out to accompany my talk. Even being very generous with the points, I believe the average was somewhere around 70%. I have come to expect such averages on exams in classes on complex topics, but not in a situation where the students are almost handed the answers. In fact, I am not convinced that I could have made it easier. One question required that they answer with "zero"; maybe they took me too literally when I said that the answer was "zero". For all the trouble I had in the first class, they actually had better grades on the worksheet, but not by much. As before, the situation just makes me question whether my instruction is that bad or if the students just don't see or don't care about an opportunity for an easy grade. Maybe it was so easy that it was demeaning.

Stemming the Tide

While not entirely relevant to high school learning, there was recently a House panel on STEM education at the college level. The participants were informative and offered suggestions on improving the declining fields.

Fixing US STEM education is possible, but will take money

In particular, I was pleased that there someone else noticed the lack of teaching preparation for graduate students. It always boggled my mind that there are stringent requirements for teacher specific education when it comes to primary and secondary schooling, but none at the collegiate level. Part of the reason I decided to participate in the TF outreach program was to become a better instructor and communicator, but I could have just as easily completed my degree with no experience in teaching whatsoever.

While it was not the focus of the panel, it is unfortunate that the article didn't place a little more emphasis on improving STEM outreach in K-12. I agree that there is a great import to retaining students at higher levels, but the Boeing representative is correct in singling out the perception of engineers by youth. I do not believe that the instruction quality in college could change appreciably in the last 40 years and yet the number of STEM degrees relative to total degrees has been falling. Something to think about.

Collisions

As a much delayed followup to my presentation on sound, today I gave a presentation on how math fits in to football. I worked on the presentation quite a bit which included several videos, an accompanying worksheet, and two live demonstrations. Molly and I discussed having the presentation run for the entire class which is the reason for the ambitious composition. I practiced the talk with some less physics-inclined friends and went to class feeling like there was some chance the subject would go over better than previous ones. Of course, everyone knows what's said about the best laid plans...

 If you'd like to see the presentation and worksheet, they're available at the following two links:

Football Presentation
Football Worksheet

Let's start our playback of today's presentation by stating that I probably bit off more than I could chew. I knew there would be problems getting students to concentrate on a single subject for more than 20 minutes (see previous talks and the field trip tours), but thought that the variety in the presentation would be enough to keep them under my thumb. Turns out that I was wrong about that. I did not get through the talk with the first class, and after some last minute changes, only eked through the second. Part of the reason for this was the prevalence of troublesome students another is that there was too much material. I got so worried about having enough material to cover the lecture that the opposite happened.

The Presentation
Whenever discussing physics or other science subjects I always hear the question, "but what does this have to do with math?" Well, usually it's not a question and is worded a bit more aggressively, but you get the point. I tried to short-circuit this sentiment by explaining that physics was simply how we use math to model the world around us. A bit general, but at least some of the students nodded their heads. To drive the point home, I described a couple of famous equations that described physical phenomena. From here I transitioned to some of the important kinematic equations that physics students first learn. I defined what each term meant and provided a written description on the back of their worksheets. We went over examples of potential and kinetic energy. Finally, I asked them to write examples of how kinematics could be related to football and then presented four examples of my own that would be the body of my talk.

The first question (one football player tackling another) was a chance to explain the conservation of moment. I began by showing them a head-on collision of two steam engines. Like all of the later video clips, it was one of the more popular parts of the talk. I made an analogy between the trains and two colliding football players, but indicated that the mass and velocities of the players would not necessarily be the same. In the first class, I attempted to lead them through the process of solving how fast one player must be going to stop another (in one dimension). In the second class, I skipped this section in an effort to save time and address the more important points of the talk. After the situation was presented, I showed them a clip of two such players colliding and asked them to make connections between the math and reality.

We next talked about conservation of energy, in the form of a car colliding with a concrete wall. I pointed out that the car had energy before the collision and asked the students to discuss and describe where that energy went afterward. At this point I ran out of time with the first class. In the second class, I continued on to described how the kinetic energy of two colliding football players could cause one to clip into the air. I had planned on calculating a specific height however, as before, the numerical part was skipped for time and clarity. Again, I included a video of a real football player getting flipped into the air.

Next up was a question on how one could throw a football as far as possible for a given amount of effort. Here, I wanted to show that while the math could be very difficult, we could use a simple experiment to approximate the result. To begin, I showed them the result of the actual derivation for range as a function of angle. This was followed by a discussion on how to model how a football player throws a ball. Eventually, with the help of several students I used a ball launcher to create a plot of range versus angle. I then showed them a plot of the functional relation derived earlier so that they could see the differences and similarities between the experiment and model.

As the talk progressed, I allowed the material to become progressively qualitative so that more advanced concepts could be addressed. I ended by trying to explain to them why spin on a football is important. Several of the students knew that a football would wobble or tumble if thrown without spin, but didn't know why it occurred. I gave a phenomenological explanation of angular momentum and some common examples. I had several students help me conduct the common demonstration of this by using a spinning bicycle wheel.

I ended by emphasizing some of the points that I thought were the most important and intentionally focused more on the basic concepts than the specific use of math or algebra.

Commentary
Talking, texting, dice throwing, and other thrown objects were a handful of all the distractions that ran throughout the talk. One student even thought it was appropriate to say "this is boring," on the start of every single slide. Molly and I did our best to contain these problems, but I tried to push on with the talk in order to cover each individual topic. On one hand, having to stop the presentation every three minutes to reprimand a student is not useful at all, but on the other if they're permitted to continue talking or doing whatever else it interrupts everyone anyway. I have some other thoughts about this issue that I'll put in a separate post, but it was a significant problem.

While I thought that the slide on the relation between physics and math would be useful, several students obviously did not pay attention or did not pay attention. I was asked about how any of the presentation was related to math on several later occasions, which was quite disappointing to hear. I tried to reiterate my initial point and while the students cared enough to comment on it, they did not care enough to hear my response.

The part addressing kinetic and potential energy went much better than I had hoped and most of the students participated readily. There was some confusion between the two, but in this case the students were mostly self-correcting. Momentum was a little less successful and I spent less time than I should have giving them a physical explanation of it. On the worksheet, I gave an example of 1 newton second being about as much "power" in a tennis ball traveling 40 miles per hour, but no one bothered to read it. I also cheated a bit by not explaining the difference between speed and velocity which I thought might have confused the issue more than it was already. The kinematic equations were accepted and the students did recognize the standard rate equation.

Most of the examples of kinematics in football were ones that the students recognized on their own. At this point, everyone was still on the same page and things were moving relatively smoothly. Conserving momentum was a little bit more difficult to get across, again because I do not think many of the students had a feel for what it is. The example dragged along painfully in the first class, especially the part about using algebra to calculate the required speed of one football player to stop another. As is good practice, I carried my variables through to the end of the calculation, but the students found it prohibitively hard to follow them. Among other problems, the students began to argue some of my points from experience. I did not have enough time to convince them that when they "dig in" they are describing a situation that's different from the model. I did try to explain that physicists use models of the world that aren't always accurate in every way so that they can first understand the principles of the system.

Conservation of energy went a little bit better, but I was still recovering from the bad experience with the momentum slides. I was relatively brief, and the topic wasn't as interesting without calculating how high a player would flip. For those looking at the slides, I included a fudge factor of 1/5 in the calculations on the slide. This is to account for other energy losses and the fact that I didn't run through an actual conservation of momentum, otherwise the returner would be flipped 20-some feet into the air.

The prelude to the best throwing angle went alright. Although, I was a bit annoyed when one student loudly accused me of showboating by displaying the derivation. The experiment was one of the highlights of the morning as several students were able to participate and almost every student was paying attention. Not only that, but the data matched my predictions quite well which provided me the opportunity to discuss modeling. The spin slides went fine and response to the demo was lukewarm. Everyone appeared to be tired by this point and I admit I was ready to be done as well.

Conclusion
I prepared too much material and glossed over some finer points in kinematics that should have been explained with more depth. I'm not sure if it is the way I present the material or if certain students lack the ability to be respectful and pay attention, but the number and magnitude of interruptions clearly aggravated confusion may have made much of what I said worthless. The students were extremely receptive to the live demonstration, but shut down soon afterward. Even now I'm frustrated with the challenge of teaching some of the students, but there were still bright spots and students that conducted themselves well.

Physical Links

I'm finishing up my presentation on physics in football and have come across a few interesting links that I thought might be nice to share.



The Naked Scientists - A large collection of podcasts, videos, and kitchen experiments that demonstrate many different scientific principles. They're put together by "media-savvy" scientists and researchers from Cambridge University. Personally, I got a kick out of the "Science Experiments from the Sporran" series, but the innuendo would be best left to more mature audiences. One experiment I quite liked was how to use buttered bread and a microwave to measure the speed of light. Overall, the site is quite well-produced and has (generally) safe and accessible experiments.



Phun and Algodoo - Both are 2D physics simulators for computers developed as side projects by a student of Umea University. The first is the more simple of the two and focuses on mechanics while the second includes more functions for fluids and the addition of light/lenses. Algodoo is also oriented toward teaching physics to students and has been optimized for Intel's classmate PC and supposedly works well with the SMART board that is in each YHS classroom. I haven't tried Algodoo yet, but Phun was extremely addictive even if the interface wasn't as intuitive as one could have hoped. It may work well as a computer lab for physics students, though I imagine one would have to assume that the students would play around with it quite a bit.