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Stats1
Flashcards do conjunto (11)
- 1What is the equilibrium state?An isolated system that is left alone for a very long time, so that the heat flow Q is equvalent with its surroundings
- 2What is thermal contact? How do we denote it as we move through time?The process of two systems exchanging energy whilst maintaining their Volume, shape and particle number
The amount of energy transferred (from Hot to cold) is given by the heat flow Q - 3What is the total energy change of a system given by?DEL E = Q - W
Where W is mechanical work done ON the system
This is the 1st law of thermodynamics - 4How can we experimentally set a fixed temperature for a system?Heat bath. Put the system onto a much larger system with a set temperature. Because the heat bath is so big, we can expect the temperature change to be a lot smaller in the bath. We can then approximate out desried system to be ~ at the original temperature of the heat bath.
- 5What is meant by a thermodynamic process?If 2 or more systems change their properties
- 6What is a quasi static process?A TD Process that happens very slowly, and starts off near equilibrium. Changes very little as it moves through time
- 7What is mechanical work? Whats is a limitation for its use?Mechanical work is the process where the particles bounce of the interface. Collectively they apply a force on the system which makes the system want to spread out where it can.
Therefore mechanical work done ON the system is given as:
W=-P* delV
These only apply for very slow processes since if we consider an instantaneous process, the particles don't have time to bounce off the system. Therefore to help remember use
dw = - PdV - 8For a large volume change what is different about the Calulation of work done?If there is a large change in volume, then perhaps there is a change in pressure as the volume changes.
We must then integrate to find the work done.
W = int( P(V) dV ) between v=v2 and v=v1 - 9What is an isothermal process? What is an adiabatic process?Isothermal process: Temperature is constant (i.e. acting on a system that is in thermal equilibrium with a bath, will stay at the same temperature as you do work on the system by other means
P*V=N*kb*T = constant
Adiabatic process: No Heat change through a thermal contact (Q=0) e.g. an insulated coffee cup (My one has the inside bit that doesn't touch the outside. It seems a good thermal insulator will always have minimal atoms in its medium so less atoms to work with.
P*V^Gamma = constant
V*T^(f/2) = constant
Deriviations in squid notes. - 10What is an ideal gas? For an ideal gas, in an isothermal environment why is there a balance point for work done on the gas?A gas where we assume consists of point particles of mass M, that DO NOT interact.
Because pressure = force/area, so the force/ pressure of the gas expansion is held at bay by an equal but opposite force from its surroundings.
From this, a stable state tells us that the pressure inside and outside the system are EQUAL as area is the same and no expansion/compression so resultant force = 0 - 11What is the ideal gas equation of state: From measured data? From theory of non ideal particles? Comparing both? What is this name?PV=N*Kb*T
PV=(3/2)*E
Found by doing the derivation from particles colliding (in Squid notes)
E = N*(3/2)*m*^2 = N*(3/2)*kb*T
Each particle has kinetic energy = (3/2)*kb*T
Or more specifically, each degree of freedom has kb*T/2 energy
This is the equipartition of energy theorem
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- FlashCards sobre Stats1, criado por Elliot Bryce em 07-11-2018.
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