Day 27: Tension Forces
College-Prep Physics: I condensed a two-day sequence on tension (from Preconceptions in Mechanics) into one. The sequence gets at the nature of the tension force (it’s the same everywhere), the mechanism for tension (i.e., how do ropes “know” how hard to pull? It’s like a series of really stiff springs), and leads students to see that Levi Strauss’s famous logo
is physically equivalent to one in which one of the horses is replaced with a tree.
We ended with this demonstration of 3 springs scales connected in series by two ropes:
What does the middle scale read?
(Here’s the answer.)