What is the internal energy of a body?
The sum of the kinetic energies of its particles’ random motion and their potential energies.
AQA A-level Physics (7408) · 3.6.2.1
Revise AQA A-level Physics (7408) specification point 3.6.2.1, Thermal energy transfer (A-level only), with free active-recall flashcards. Flip through the set or review every question and answer below.
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What is the internal energy of a body?
The sum of the kinetic energies of its particles’ random motion and their potential energies.
What does the potential-energy contribution to a body’s internal energy depend on?
The particles’ relative positions and interactions.
What does the first law of thermodynamics say about a system’s change in internal energy?
It equals the net energy transferred between the system and its surroundings by heating and work, expressing conservation of energy.
How does energy transfer by heating affect a system’s internal energy?
Heating the system increases its internal energy; energy transferred from it by heating decreases it.
How does work affect a system’s internal energy?
Work done on the system increases its internal energy; work done by the system decreases it.