Day 19: Put On Your Physics Goggles
College-Prep Physics: I didn’t anticipate spending a whole period about how a fan cart works. Nor was I expecting students to say a fan cart’s speed would accelerate up to a constant speed.
Transfer is hard. We had already done the bowling ball and mallet activity. But this wasn’t a bowling ball. It was a fan cart. In their minds, different objects means different outcomes.
That’s when I came up with the idea of “physics goggles.” When you’re wearing your physics goggles, you see past the superficial features of different situations and focus on the underlying principles. In the case of the fan cart, the air molecules were providing the “taps” to accelerate the cart. And since those “taps” never stop, the cart would continually increase speed, just like a tapped bowling ball.
While students agreed that you could get the bowling ball to go as fast as a Ferrari (even with tiny taps, as long as you could keep up with the ball), they initially struggled with the fan cart going as fast as a Ferrari. Most thought the top speed of the fan cart was determined by the speed of the fan.
“Time to put on our physics goggles!”