# Day 82: Starting Circular Motion

**Posted:**February 4, 2014

**Filed under:**School Days |

**Tags:**CFPM 1 Comment

Today we played on spinny chairs to investigate centripetal acceleration. We first went through setting up the Labquests, learning the basics of how an accelerometer measures acceleration, and identifying the direction of +x and +y. Then I had them predict what they thought the x and y accelerations would look like, informally. Some student sketches below.

First note: we really need to work on correctly labeling our graphs. At any rate, is is rare for students to correctly predict that they will see a negative y acceleration and zero x acceleration. After predictions, I had them spin (as fast as possible and with arms as outstretched as possible, and keeping the Labquest as level as possible) and we had a conversation about what they found. (Note: I found that we actually get better results just standing and spinning…not near as fun, but far less noisy of data)

[…] to eliminate the spin up process from data collection. I ask them to graph what they will see; most think it will be sinusoidal. Then students actually do the trial, and sketch what they see. It takes a lot of individual […]