In physics, students are developing understanding through experimentation.

Take a dollar bill---or even better, a twenty-dollar bill. Smooth it out so it is almost flat. Dangle it between a friend's thumb and forefinger, and make a risky wager: if they can catch it between their thumb and forefinger when you release it without warning, it's theirs to keep.

This activity forms the motivation for understanding kinematics, reaction times, errors in experiments, and the basis of measurement in the physical sciences. In physics class this block, we are developing the mathematical description for motion, which is the study of kinematics, and the physical laws underlying it, which are motivated by analyzing experiments in momentum. Students have built paper cones and released them from various heights to observe the remarkable fact that they fall quite differently from a dropped paper weight. They have timed a child’s toy to observe constant velocity motion using modern tools like motion sensors and ancient tools like the meter sticks. In the process, they have not only probed questions about physical measurement but also generated new ones.

The exploration on momentum revisits an intriguing toy called Newton’s cradle and repurposes it by studying its motion with a high-speed camera. The students have been analyzing the video data with an open-source tool called Tracker, and they are finding out that there is a supreme court in science-–-it is experiment!

When not thinking about experiments, the students have been actively engaged in class through peer instruction. A multiple choice question about their reading or short lecture is presented to the class. Students think about the question individually and then hazard a guess by voting in an increasingly democratic classroom setting. There is typically a spread in the results, and then the class gets into heated discussions in which students have to convince each other their viewpoint is the correct one. A vote is taken again, and the consensus reached demonstrates how remarkably well students can teach other.

In the upcoming build week at the end of block 1, we are going to custom-build a Newton’s cradle to address some of the more intricate questions that the students are already asking, and we will pry open our discussion of energy, the next conceptual cornerstone in our study of mechanics.

-- Kaushik Basu