Day 77: Falling Toilet Paper Rolls
Another practicum in AP today:
Two rolls of toilet paper are dropped at the same time. One falls freely. The other unrolls. Students calculated how to stagger the drop heights so the rolls hit the ground at the same time.
Two groups took a conservation of energy approach. One group took a dynamics (torque) approach. All three groups arrived at the same ratio of heights. But was their prediction correct? Watch the video and see!
I blogged about this previously: http://fnoschese.wordpress.com/2010/12/17/falling-rolls/