HL IB Physics Thermodynamics

These flashcards cover the key vocabulary terms and concepts from the HL IB Physics Thermodynamics lecture notes to aid in exam preparation.

Thermodynamic Systems

Systems that determine the energy changes involved in physical processes.

First Law of Thermodynamics

Energy supplied to a system equals the change in internal energy plus the work done on or by the system (Q = ∆U + W).

Entropy

A measure of the amount of disorder or randomness in a system.

Change in Internal Energy (∆U)

The result of heat added to the system minus the work done by the system.

Ideal Gas

A theoretical gas composed of many particles that are in constant random motion and interact only through elastic collisions.

Work Done by a Gas (W)

The energy transfer that occurs when a gas expands or compresses against an external pressure.

Isobaric Process

A process that occurs at constant pressure.

Isovolumetric Process

A process that occurs at constant volume.

Isothermal Process

A process that occurs at constant temperature.

Adiabatic Process

A process in which no heat is transferred into or out of the system.

Carnot Cycle

An idealized thermodynamic cycle that provides the maximum possible efficiency for a heat engine.

Boltzmann Constant (k_B)

A physical constant that relates the average kinetic energy of particles in a gas with the temperature of the gas.

Ideal Gas Constant (R)

The constant that appears in the equation of state for an ideal gas (approximately 8.31 J/(mol K)).

Heat Engines

Devices that convert thermal energy into mechanical work through cyclic processes.

Efficiency of Heat Engines

The ratio of useful work output to the total energy input, expressed as η = Wout / QH.

Clausius Form of the Second Law

Thermal energy cannot spontaneously flow from a region of lower temperature to a region of higher temperature.

Kelvin Form of the Second Law

It is impossible to convert all thermal energy extracted from a reservoir into work.

Microstate

A specific configuration of a system at the microscopic level.

Entropy Change (∆S)

The change in a system's entropy, calculated as ∆S = ∆Q / T at constant temperature.

Thermodynamic Processes

The various types of changes that a thermodynamic system can undergo.

Heat Transfer (Q)

The transfer of thermal energy from one physical system to another.

Internal Energy (U)

The total energy contained within a system due to the kinetic and potential energy of its particles.