Thermal Physics:
Solids vibrate about their fixed positions
Liquids can move freely
Gases move freely rapidly and randomly
Pressure is force per unit area
internal energy is the sum of potential energies and kinetic energy.
A rise in temperature increases the kinetic energy so the internal energy increases
A change of state increases potential energy so internal energy increases
Thermal energy is transferred from a region of higher temperature to a region of lower temperature.
Regions of equal temperature are said to be in thermal equilibrium
There is an absolute scale for temperature that does not depend on the property of any material.
T (K) = degrees Celsius + 273.15
Absolute zero (0K) is the temperature at which a substance has minimum internal energy.
Specific heat capacity is the amount of thermal energy required to increase the temperature of a unit mass by a unit temperature rise.
E = mcT
Latent heat of fusion is the energy required to change a solid to a liquid whilst the temperature remains constant.
Latent heat of vaporisation is the energy required to change a liquid into a gas whilst the temperature remains constant.
Boyle's law states that the volume of a fixed mass of gas is inversely proportional to the pressure exerted on it provided that the temperature is kept constant.
For a fixed mass of an ideal gas at constant pressure, its volume is proportional to the ideal gas temperature in Kelvin.
Pv/T = constant
one mole of a substance contains 6.02x10^23 particles and this is Avogadro's constant
Kinetic model assumptions:
The molecules of the gas are in rapid random motion
The volume of the molecules are negligible compared to the volume of the body.
They undergo perfect elastic collisions
They exert no forces on other molecules or the body except during collisions
The time spend in collisions is small compared to time between them.
PV = NkT PV = nRT
where p is pressure, v is volume, N is number of molecules, k is the boltzmann constant, T is the temperature in kelvin, n is number of moles, R is the molar gas constant.
The mean translational energy of an atom of an ideal gas is directly proportional to the temperature of a gas in kelvin.
E = 3kT/2
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