Thermal Physics Flashcards
energy transfer between two objects takes place if:
- one object exerts a force on the other one and makes it move.
- one object is hotter than the other so heat transfer takes place by means of conduction, convection or radiation
internal energy
is the energy of its molecules due to their individual movements and positions.
it basically is the sum of the random distribution of the kinetic and potential energies of its molecules.
thermal energy
the internal energy of an object due to its temp.
example of filament light
the internal energy of a lamp filament increases when the lamp is switched on because work is done by the electricity supply pushing electrons through the filament. the filament becomes hot as a result. when it reaches its operating temp., heat transfer to the surroundings takes place and it radiates light. work done by the electricity supply pushing electrons through the filament is balanced by heat transfer and light radiated from the filament.
specific heat capacity
the amount of energy needed to raise the temp. of 1 kg of the substance by 1 K
energy change = ?
mc delta T
ml
specific latent heat
specific latent heat of fusion and vaporisation is the quantity of thermal energy required to change the state of 1 kg of a substance
Temperature
is a measure of the degree of hotness of the object. the hotter an object is, the more internal energy it has.
thermal equilibrium
there is no heat transfer take place at the same temperature
absolute zero
an object at absolute zero has minimum internal energy
boyle’s law
at a constant temp. the pressure p and volume V of a gas are inversly proportional.
pV = ?
constant
charles’ law
at constant pressure, the volume V of a gas is directly proportional to its absolute temp.
V/T = ?
constant
