Thermodynamics

• isotropic solid and moderate temperature changes.

applies during a phase change at approximately constant temperature.

In a thermally insulated system

For a fixed amount of ideal gas

• monatomic ideal gas.

Convention: $W>0$ when the gas does work on the surroundings.

Convention: $Q>0$ enters the system and $W>0$ is work done by the system.

• absolute temperatures in kelvin.