NapkinCalc

Physics 2 — Momentum & Waves

Collisions & conservation of momentum, circular motion, and waves — frequency, wavelength, and harmonics.

Physics 1 tracked one object. Now things interact: collisions trade momentum, circular motion needs a steady inward pull, and waves carry energy without carrying matter. Same rules as before — just more players.

  1. 01 Momentum & impulse Momentum p = m·v is "quantity of motion" — and the only way to change it is a force acting for some time: the impulse J = F·Δt. A small force for a…
  2. 02 Collisions — momentum is conserved When two things collide, the total momentum before equals the total after — no exceptions. If they stick together (a perfectly inelastic collision), one…
  3. 03 Circular motion Going in a circle at constant speed is still accelerating — the direction changes, and that takes a force pointed at the center: F = m·v²/r. Lose that force…
  4. 04 Waves Every wave obeys one bookkeeping rule: v = f·λ. Speed is set by the medium, frequency by the source — so wavelength is what adjusts. Sound in air:

next course: Physics 3 — Electricity & Magnetism →