Week 8: Rotation II & Springs

Last week ("Rotation I"), we focused on rotational kinematics, rotational kinetic energy, and torque.

This week —

• For "Rotation II" (one worksheet), we'll focus on angular momentum and how it's conserved in collisions.
• For "Springs" (two worksheets), we'll focus on:
  • The force applied by a stretched/compressed spring.
  • The energy stored in a stretched/compressed spring.
  • "Simple harmonic motion" (think period, amplitude, etc. when a mass is attached to the end of the spring).
  • (Tip: I highly suggest you be comfortable with both horizontally and vertically mounted springs! But no need to worry about friction for this week's problems, I'm not sure if it'll come up in homework though.)

[1] Helpful Resources⚓︎

• For angular momentum...
  • Rotation, Page 5 (Videos 29 to 37) — Angular momentum, angular momentum conservation, angular impulse
• For springs...
  • [Force/Energy...]
    • Work and Energy, Video 13 — Hooke's Law and Elastic Potential Energy
    • Work and Energy, Video 14 — A Hooke's Law Problem
    • Work and Energy, Video 16 — Conservation of Energy: Vertical Spring Problem
    • Work and Energy, Video 17 — Conservation of Energy: Bungee Jump Problem
      • (Not strictly necessary, but a good practice problem.)
    • Work and Energy, Video 19 — Units
      • (Not strictly necessary, but it's only three minutes long.)
  • [Simple Harmonic Motion...]
    • Simple Harmonic Motion, Page 1 (Videos 1 to 7) — SHM basics, spring-mass oscillator

[2] Recitation Prep⚓︎

I recommend reviewing the following concepts, they will probably come up in recitation:

• Conservation of angular momentum, specifically when two objects stick together like this (although the exact object shapes/speeds will be different).
• Object launched by a spring.
• SHM for object attached to a spring.