I have really come to love Twitter for the way I can use it as an on-going source of professional development, and Wednesday’s AP Physics 1 with Precalculus Honors course is my latest, greatest example of why.
It all started Tuesday night when Frank Noschese (@fnoschese), a physics teacher in New York, retweeted something from Monica Owens (@MonicaKonrath), a physics teacher in Indiana. First of all, I’ve never met either of these people, but without them Wednesday’s class wouldn’t have happened. Anyway, here’s her original tweet:
Now, our plan for Wednesday, which was our class’s last meeting of the term, was to give a couple quizzes, work for a while on momentum problems, and then continue our open inquiry on polynomial equations. This activity sounded way more fun, and I really liked the idea of looking at texting while driving right before the students leave for break, so we decided on the fly to do this instead. The results were even more amazing than we’d hoped.
We started with a simple question: “If you sent a text message while you were driving, how far would you travel while sending the message?” They looked at us for a couple seconds, then turned to their groups, and what followed was music to our ears:
- “We’re going to need to make some assumptions.”
- “If the velocity is constant then we can ignore acceleration.”
- “Let’s run some trials to see how long it takes to send a text.”
It really is quite a nice gift to hear that the students have internalized at least some of the things we’ve been working on all year. Because things were going well, my teaching partner suggested we add a second question: “Suppose you collide with a stopped car while you’re sending that text. How much force will the seat belt exert on you?”
This is a nice little momentum/impulse question that extends the life lesson we’re trying to get at with this problem, and it was once again a joy to see that they immediately recognized it as such and went to work on it. When all was said and done, we had a nice collection of whiteboards to share. Here are a couple of them:
We finished up by trying to give the students some context. First, we did some quick unit conversions so they could see that the force of the seat belt is the equivalent of having 1000 pounds or more sitting on your chest. Second, we took a little field trip to the street that borders the school, where the speed limit happens to be the same as the one assumed by the white board above. We measured out 80 meters so they could see how far that really was. We then noticed that in this distance there were seven cars parked by the side of the road, any of which a driver might hit while looking down. We also saw two pedestrians, one jay walker, and an illegal U-turn, which were just additional opportunities for a terrible accident.
It really was a lot of fun, and we think pretty powerful, to tie the physics we’ve been doing to a real world issue that teenagers (should) hear a lot about, and it was a great way to close out the month. Thank you, PLN, for bringing me just the right activity at just the right time. Happy holidays to all.