Thermal Physics Flashcards
The specific heat capacity of a substance
The specific heat capacity of a substance is the amount of energy required to raise the temperature of 1 kg of a substance by 1 Kelvin.
Specific latent heat of fusion (solid to liquid) or vaporisation (liquid to gas)
Specific latent heat of fusion or vaporisation is the amount of energy needed to change the state of 1kg of a substance without the change of temperature.
Internal Energy
The sum of the kinetic and potential energies of its particles
Assumptions in kinetic theory
All molecules of gas are identical.
The gas contains a large number of molecules.
Molecules have a negligible volume compared to the container.
The molecules move about randomly.
Newtonian mechanics occurs.
All collisions are perfectly elastic.
Molecules move in a straight line between collisions.
The forces that act during collisions last for much less time than the time between collisions.
Boyle’s Law
pV=constant
The pressure p of a fixed gas at a constant temperature is inversely proportional to its volume V
Charles’s Law
V/T=constant
The volume V of a fixed mass of gas at a constant pressure is directly proportional to its absolute temperature T
Pressure Law
p/T=constant
The pressure of a fixed mass of gas at a constant volume is directly proportional to its absolute temperature
Brownian motion
The random and unpredictable motion of a particle caused by the molecules of the surrounding substance colliding at random with the particles
1st law of thermodynamics
The heat energy supplied to a system is equal to the rise in internal energy plus the work done by the system on its surroundings
Ideal gas
pV=nRT
An ideal gas is one which obeys Boyle’s law
Absolute zero
The lowest possible temperature and the temperature at which the object has minimum internal energy
