# Thermal Physics

?
When there is a sudden change in pressure, by which no heat is transferred into or out of the system. Q=constant.
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What is the 1st Law of Thermodynamics?
Delta U = Delta W + Delta Q (U=internal energy; W=work done; Q=heat transferred)
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What is the 2nd Law of Thermodynamics?
The entropy (S) of the universe is always increasing.
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Define HEAT
Amount of energy transferred across a temperature difference.
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Define temperature
A measure of the average kinetic energy of particle sin a system
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What is latent heat? State the equation.
The heat required to change the phase of the substance. (change in Q = mL)
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What is meant by an Ideal Gas?
One that obeys the ideal gas equation: PV = nRT. Attractions between particles are negligible. Volume of the particles compared to the total volume in negligible. The collisions are elastic. The time of a collision is negligible.
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What is the purpose of the Maxwell-Boltzman distribution graph?
Shows the average kinetic energy of the system. (No. of particles = y axis; (kinetic) energy = x axis)
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What is state?
Specific values of P, V and T that describe a system.
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Name another formula for KE other than 1/2 mv^2
KE = 3/2kT
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What is k in the equation KE = 3/2 kT
k = Boltzmann's Constant = 1.38 * 10^-23
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Charles' Law?
ISOBARIC (Volume on the y axis, temperature on the x axis) = CONSTANT PRESSURE
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Gay-Lussac's Law?
ISOCHORIC (Pressure on the y axis, temperature on the x axis) = CONSTANT VOLUME
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Boyle's Law?
ISOTHERMIC (Pressure on the y axis, volume on the x axis) = CONSTANT TEMP
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What is c in the formula Mc(delta)T. State its units.
Specific heat capacity (J kg^-1 K^-1)
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A device that converts heat into mechanical work is called what?
A heat engine.
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Describe typical steps of a heat engine's process
1) Heat is taken into the engine (from hot reservoir of assumed fixed temp) . 2) Q heat enters the engine, a part is converted to mechanical Work, what is left is heat the engine rejects. 3) Rejected heat goes to reservoir of lower temp.
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What equation can be used to calculate an engine's efficiency?
efficiency = W/Q. Efficiency = (energy entered from hot reservoir - energy rejected)/Total energy entered from hot reservoir
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Energy degradation refers to what happening to the energy
It becomes less useful, as a consequence of the second law of thermodynamics
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A gas compressed isothermally so that an amount of work = 6500J is done. How much heat is taken out or given to the gas
No heat. Isothermic. Therefore, no temperature change. U = W
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## Other cards in this set

### Card 2

#### Front

What is the 1st Law of Thermodynamics?

#### Back

Delta U = Delta W + Delta Q (U=internal energy; W=work done; Q=heat transferred)

### Card 3

#### Front

What is the 2nd Law of Thermodynamics?

#### Back ### Card 4

Define HEAT

#### Back ### Card 5

#### Front

Define temperature

#### Back 