MCAT physics 2

Thermodynamics - the study of heat transfer and its effects.

Calorie (C)- Quantity measure of heat = 10³ calories = 4.134 x 10³ J

Temperature (T) - a measure of the KE (heat content) of particles

Kelvin: the most commonly used temperature unit with 0K = absolute zero

T_K = T_C + 273

Conduction - the transfer of energy via molecular collisions

Convection - the transfer of heat through fluids (gas, liquid or super-critical fluids) by the physical motion of the fluid

Radiation - the transfer of energy via electromagnetic waves of motion...only form possible of energy transfer in a vacuum.

• 1^st Law: The change in internal energy (U) of a system is equal to the heat (Q) transferred into the system, minus the energy lost by the system when it performs work (W).
• U = Q - W

Adiabatic Processes: Q = 0 ... W = -U

Isovolumetric Processes: W = 0 ... Q = U

Closed Cycles: U = 0 ... Q = W

2^nd Law: The universe always tends towards an increase in entropy

Entropy: A measure of the dispersion of energy of a system