This morning in the physics class, the students were given a question: if you were an astronaut working on a satellite, and your line back to the space shuttle is cut, how could you get back to the space shuttle? The students gave a good answer: push off the satellite and aim yourself back to the space shuttle.
This was a good setup to get students thinking about some big new physics ideas about impulse and momentum. Given the strength of your legs, and the time you spend pushing off the satellite, how fast will you go after you push off? And, because of Newton’s Third Law, the satellite is also pushing off you as you push off it – how fast will the satellite go?
I like this lesson because it builds off of what they learned last week about Newton’s Laws. Now that they have lots of practice thinking about these physics principles, they get new puzzles and scenarios where they have to use these physics principles. Now, they have to use last week’s Newton’s Laws simultaneously with the new ideas about impulse and momentum – and, as they work the problem, they find out that these ideas put together lead them to a very important new physics rule, the conservation of momentum.
As they work problems and watch demonstrations this morning, I can already see wheels turning. They’re thinking about collisions, and forces, and how they can cushion an impact. Right now, this is just on paper (or just in a demonstration the teacher is doing), but tomorrow, they will do a classic “egg drop” challenge, where they need to make a contraption so an egg can get out of a 15-foot drop unscathed. After taking these ideas from problems on paper, about time of impact and the force needed to stop something, they will see what they can rig up in the lab to put these ideas into practice.
I also got to have a lot of fun with the students last night where I joined in with the counselors to run an optional afternoon activity. By student request, I offered a lesson on “Introduction to Spacetime and Black Holes,” and last night’s group of campers were one of the most attentive lecture audiences I’ve ever had! I can see that their enthusiasm is contagious, and that they’re learning a ton from their classes and from each other.
