Angular kinematics, torque, rotational inertia, equilibrium, and Newton's laws in rotational form — every linear concept gets a rotational twin.
🎙 Episode 5
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What's in this episode
0:00 – Intro — Why rotation is just linear motion in disguise
2:00 – Rotational kinematics (5.1) — Angular position, velocity, acceleration; the same equations in disguise
6:00 – Connecting linear and rotational (5.2) — v = rω and friends; the bridge equations
10:00 – Torque (5.3) — τ = rF·sin(θ); why doors have handles far from hinges
14:00 – Lever arm intuition — When force creates zero torque (and why)
17:00 – Rotational inertia (5.4) — I = Σmr² and why mass distribution matters more than total mass
21:00 – Why skaters spin faster pulling in arms — A preview of angular momentum (Unit 6)
24:00 – Rotational equilibrium (5.5) — Στ = 0, seesaws, and the recipe for balance problems
28:00 – Newton's 2nd law (rotational) (5.6) — τ_net = Iα, the rotational F = ma
31:00 – Wrap-up — The 3 big ideas in one minute
How to use the podcast
First listen: Play at 1× speed with no distractions. Don't try to take notes — just absorb the linear-to-rotational analogy.
Second listen: Speed up to 1.25× or 1.5× and follow along with the Cheat Sheet open. Pause at the analogy table and make sure you've got every row.
Right before the exam: Play at 1.5–2× as background while reviewing flashcards. Unit 5's central trick is the translation table — repetition makes it automatic.