Physics #3 Flashcards
the zeroth law of thermodynamics
2 objects in thermal equilibrium will not participate in heat exchange.
Also, if a=b and b=c then a=c.
at the molecular level, temperature if proportional to the _______
average kinetic energy of the particles that make up the substance.
thermal equilibrium occurs when ____ heat is transferred between two objects in thermal contact
no
the third law of thermodynamics
the entropy of a perfectly organized crystal at absolute zero is 0.
how does a material’s linear expansion coefficient compare to its volumetric expansion coefficient?
Beta = 3xalpha
is there a maximum distance at which thermal contact does not exist?
no, thermal contact will always exist no matter how far apart two objects are. It might just be very very miniscule at large distances.
compare the length change of 2 objects that differ starting lengths but increase temperature the same
the object that was longer to start will undergo a greater change in length (formula)
accuracy is related to an ____, not a scale
instrument
isolated system
cannot exchange energy or matter with the surroundings
in an isolated system, internal energy change = ___
0
____ are thermodynamic properties that are a function of only the current equilibrium state of a system, while ____ describe the path taken to get from one state to another
state functions
process functions
list the state functions
pressure, volume, density, temperature, enthalpy, internal energy, gibbs free energy, entropy
list the process functions
heat and work
first law of thermodynamics
internal energy conserved
mechanical energy conserved when no nonconservative forces present
what can lead to an increase in the internal energy of a system
increase in heat or work done on the system.
second law of thermodynamics
objects in thermal contact and not in thermal equilibrium will exchange heat energy such that the object with the higher temperature will give off heat energy to the object with a lower temperature until both objects have the same temperature at thermal equilibrium
energy is spontaneously dispersed from being localized to becoming spread out of it is not hindered from doing so.
the energy of the universe is increasing
what is heat?
the process by which a quantity of energy is transferred between two objects as a result of a difference in temperature.
describe conduction
need direct physical contact: kinetic energy is transferred from particles of the hotter matter to particles of the cooler matter
describe convection
the transfer of heat by the physical motion of a fluid over a material
describe radiation
transfer of energy by electromagnetic waves
only ____ and _____ can transfer heat by convection
liquids and gases
which type of heat transfer does not need matter to transfer heat?
radiation
define the specific heat of a substance
defined as the amount of heat energy required to raise 1 g of a substance by one degree Celsius.
will the temperature of a substance start to increase before all of the solid is changed to liquid?
no, all solid must be changed to liquid before the substance will begin to rise in temperature.
