Day 10: Dueling Rubber Bands
College-Prep Physics: We’ve been using the Preconceptions in Mechanics bridging analogies and voting discussions to explore normal forces. Yesterday we discussed whether a table pushes up on a book. Today we discussed whether those forces are equal in size. Part of the equality discussion involved the rubber bands and small key ring pictured above.
There’s a stiff thick rubber band on the left of the ring, and a flexy thin rubber band on the right. The ring is at rest. Which rubber band pulls harder on the ring? How do you know? Why does one rubber band stretch more than the other? How do the rubber bands “know” how hard to pull?