Thermodynamics — Energy & Cycles
The first law, specific heat, the ideal gas law, heat-engine and Carnot efficiency, the fridge COP, and heat conduction — energy bookkeeping with units enforced.
Thermodynamics is the accounting of energy — where it goes, how much you can recover as useful work, and the hard limits nature puts on that. It runs every engine, power plant, fridge, and heat pump on Earth. The whole subject is bookkeeping, and bookkeeping is exactly what this app is for.
- 01 The first law — energy is conserved ELI5: energy is never lost, only moved. Add heat Q to a gas and it either raises the internal energy U or does work W pushing a piston: ΔU = Q − W. That's…
- 02 Specific heat — how much energy to warm something ELI5: water is stubborn to heat; metal is easy. Specific heat c is how many joules raise one kilogram by one kelvin, and Q = m·c·ΔT is the total. Water's…
- 03 The ideal gas law — pressure, volume, temperature ELI5: for a gas, P·V = m·R·T ties pressure, volume, mass, and temperature into one equation — squeeze it, heat it, and the others respond. Here R is the…
- 04 Heat-engine efficiency — and Carnot's hard ceiling ELI5: an engine takes in heat Q_hot, dumps some as waste Q_cold, and keeps the rest as work. Efficiency η = W / Q_hot. But Carnot proved no engine beats η = 1…
- 05 The fridge run backwards — coefficient of performance ELI5: a fridge is an engine in reverse: spend work to move heat from cold to hot. Its COP = T_cold / (T_hot − T_cold) is often well above 1 — you move several…
- 06 Heat conduction — the rate heat leaks ELI5: heat flows through a wall at a rate Q/t = k·A·ΔT / L — faster through a thin, conductive, large, hot-on-one-side wall. The conductivity k is why a steel…
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