Laws of thermodynamics, heat engines, and entropy concepts for a college physics sequence.
41 cards · basic cards · AI-written, checked twice. Edit anything.
- What does the First Law of Thermodynamics state?
Show answer
Energy cannot be created or destroyed, only converted from one form to another. In a system, the change in internal energy equals heat added minus work done by the system.- Write the First Law of Thermodynamics as an equation.
Show answer
ΔU = Q - W, where ΔU is change in internal energy, Q is heat added to the system, and W is work done by the system.- Define internal energy in a thermodynamic system.
Show answer
The total energy contained within a system due to the random motion of its molecules, excluding macroscopic kinetic and potential energy.- Define entropy.
Show answer
A measure of the disorder or randomness in a system, related to the number of microscopic states a system can occupy at a given macroscopic condition.- What does the Third Law of Thermodynamics state?
Show answer
The entropy of a perfect crystal at absolute zero (0 K) is zero. As temperature approaches absolute zero, entropy approaches a constant minimum.- State the Zeroth Law of Thermodynamics.
Show answer
If two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other. This defines temperature as a fundamental quantity.- What is absolute zero in Kelvin?
Show answer
0 K, which equals approximately -273.15 degrees Celsius or -459.67 degrees Fahrenheit.- Define a reversible process in thermodynamics.
Show answer
A process where the system remains in equilibrium throughout and can be reversed by infinitesimal changes to external conditions, returning both system and surroundings to initial states.- Define an irreversible process in thermodynamics.
Show answer
A real process where the system is not in equilibrium and cannot be reversed to return both system and surroundings to their initial states.- What is heat in thermodynamics?
Show answer
Energy transfer between a system and its surroundings due to a temperature difference. Heat flows spontaneously from higher to lower temperature.- What is work in thermodynamics?
Show answer
Energy transfer due to a force acting through a distance. In thermodynamics, it typically refers to expansion or compression work done by or on a gas.- What is an isothermal process?
Show answer
A thermodynamic process where temperature remains constant throughout. For an ideal gas, ΔU = 0, so Q = W.- What is an adiabatic process?
Show answer
A thermodynamic process where no heat is exchanged between the system and surroundings (Q = 0). Work done equals the change in internal energy (W = -ΔU).- What is an isobaric process?
Show answer
A thermodynamic process at constant pressure. The work done by the gas is W = P times ΔV.- What is an isochoric (isovolumetric) process?
Show answer
A thermodynamic process at constant volume (ΔV = 0). No work is done by or on the gas (W = 0).
FlashKeepers