MCAT Physics

Thermodynamics

MCAT Physics > Thermodynamics

Background

Zeroth Law of Thermodynamics states that there must be a conservation of heat between objects in thermal equilibrium (no net heat exchange, concept of temperature)

Temperature (T) is the average kinetic energy of molecules. Heat flows from high temperature (hot) to low temperature (cold). Length, volume, and conductivity all increase as temperature increases

The Kelvin Scale (K) has the zero reference point at absolute zero (no thermal energy)

TC = TK – 273

Thermal Expansion is the property that involves the increasing of the length or volume of a piece of matter as the temperature increases

Thermodynamics - Thermal Expansion

ΔL = αLΔT (Solids)

ΔV = βVΔT (Gases)

Heat Exchange Methods

Thermodynamics - Conduction, Convection and Radiation

Conduction is the direct transfer of heat from molecule to molecule through collisions or other direct physical contact (solids)

Convection is the process of transferring heat through the physical motion of the heated material, usually a fluid. The heated portions rise and the cooled portions sink. This occurs is because density decreases with temperature

Radiation is the transfer of energy by electromagnetic waves

Laws of Thermodynamics

See Laws of Thermodynamics

MCAT Physics

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