Reel It In: Why Does Pulling In Speed Up a Spin?
Sim Lesson
Students use the Reel It In simulation to spin a ball on a string, reel the string in to shrink the circle, and observe the spin speed up, then cut the string and watch the ball fly off in a straight line. Lesson Purpose Students often think an object let go from a spin flies straight outward, and are surprised that pulling it inward speeds it up. Watching both builds intuition for how spinning motion behaves.
A figure skater spins slowly with arms out, then pulls them in and suddenly spins much faster, without anyone pushing. A ball whirling on a string does the same thing. Why does pulling in speed up a spin? In this lesson, you will use the Reel It In simulation to whirl a ball on a string and reel it in while it spins.
Topics and standards: Science, Energy, Physics, Physical Science, Mechanical Energy, Simulation, Motion, Forces & Motion, Grades 9-12, Forces, AP Sciences, SC.912.P.12.6, TEKS Science PHY.5.D, PHYS1-PS2-13