# Day 10: Energy Intro

(1) What do you observe?
(2) What do you think might be happening?"

In one class, every group said energy transfers from one pendulum to the other and back again. In my other class, each group said something different: force caused motion to transfer, energy transferred, vibration transferred, forces interacted, something about weight, and something about inertia?? (pendulum on left was at rest until right pendulum acted on it).

In the first class, I asked them to make an energy pie chart…and no sooner had I said "pie" when a student immediately said "Wouldn't a line graph be better since it's changing over time?" So I ran with it, and skipped pies in the second class and went steady to the line graph.

I asked for two lines on the graph, one for each pendulum. Later, I asked them to add a line that represented the sum of the energies.

Pictured is one group's work.

(Note: We haven't defined energy in class yet. I just wanted to see where they are new and what they would draw. One student realized we didn't have a way to measure energy yet, so we were arguing over something we couldn't verify…

Yet!)