Second law and engines (AQA A-Level Physics): Flashcards

Must operate between hot source and cold sink

Energy must be transferred to sink, can't all be used as work

$\frac{W}{Q_H}$ or $\frac{Q_H - Q_C}{Q_H}$

Heat energy absorbed from the source

Heat energy lost to the sink

$\frac{T_H - T_C}{T_H}$

Kelvin

High $T_H$ (source temp) and low $T_C$ (sink temp)

Frictional forces consume energy

System capturing waste heat to heat buildings