Unit 03 · Physics 2
Fluids & Thermal Physics
Pressure in a still fluid and a moving one, then what a few hundred molecules in a box have to do with temperature, heat and engines.
Work through them in order: each lesson assumes the one before it. Every lesson asks you to commit to a prediction, then lets you test it against a simulation of the real equations.
- 01
Pressure & Buoyancy
One number decides sinking and floating, and neither the object's weight nor its depth is anywhere in it.
Topics: Pressure at depth · Buoyant force · Archimedes' principle · Floating
26 min3 checkpoints - 02
Fluid Flow & Bernoulli's Equation
Squeeze a pipe and the water speeds up, and the pressure, against most people's instinct, falls.
Topics: Continuity equation · Bernoulli's equation · Flow uphill · Assumptions and limits
22 min3 checkpoints - 03
Heat & Thermal Equilibrium
Two bodies always end at one temperature, and almost nobody guesses which one, or why melting ice takes in heat without warming up.
Topics: Heat and temperature · Thermal equilibrium · Heat capacity · Phase change
30 min3 checkpoints - 04
Kinetic Theory & the Gas Laws
A few hundred hard discs in a box, and the gas law falls out of them without ever having been assumed.
Topics: Pressure from impacts · Temperature and kinetic energy · Speed distribution · The ideal gas law
28 min4 checkpoints - 05
Thermodynamic Processes & Engines
Four processes, one energy ledger that always closes, and a ceiling on efficiency that no engineer will ever lift.
Topics: The first law · Four processes · Work on a PV diagram · Carnot efficiency
23 min4 checkpoints