Newton's laws, free-body diagrams, gravity, normal force, friction, springs, and circular motion — the heaviest unit on the exam.
🎙 Episode 2
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What's in this episode
0:00 – Intro — Why Unit 2 is the heaviest single unit on the exam
2:00 – Systems and center of mass (2.1) — Treating a group of objects as a point
4:00 – Forces and free-body diagrams (2.2) — The most important problem-solving tool
7:00 – Newton's third law and tension (2.3) — Forces come in pairs; tension in strings
10:00 – Newton's first law (2.4) — Equilibrium and inertia
12:30 – Newton's second law (2.5) — F = ma, the master equation
16:00 – Gravitational force (2.6) — Weight, apparent weight, and the equivalence principle
20:00 – Friction (2.7) — Static vs. kinetic, and the coefficient
23:00 – Spring forces (2.8) — Hooke's law and restoring force
25:00 – Circular motion (2.9) — Centripetal acceleration and the role of force
28:30 – 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 connections between Newton's three laws and the common forces.
Second listen: Speed up to 1.25× or 1.5× and follow along with the Cheat Sheet or Essentials page open. Pause when you hit a force you're shaky on.
Right before the exam: Play at 1.5–2× as background while reviewing flashcards. Unit 2 has the most material to remember of any unit — repetition really helps.