Define internal energy .

The internal energy of a system is the sum of the random distribution of kinetic and potential energies within a system of molecules.

State two ways the internal energy of a system can increase.

Doing work on it Adding thermal energy to it (heating it)

State two ways the internal energy of a system can decrease.

Losing thermal energy to its surroundings The system doing work on the surroundings (e.g. a gas pushing a piston)

The internal energy of a system is the sum of the random distribution of .......... and potential energies within a system of molecules.

The internal energy of a system is the sum of the random distribution of kinetic and potential energies within a system of molecules.

True or False? For an ideal gas heated from 50 °C to 150 °C, the internal energy triples.

False. Internal energy is proportional to thermodynamic (kelvin) temperature , not the Celsius value. Converting to kelvin (323.15 K to 423.15 K) gives a ratio of only about 1.3, so the internal energy does not triple.

What is the total internal energy of an ideal gas equal to, and why?

The total kinetic energy of its molecules, since an ideal gas has zero potential energy .

A LevelPhysicsCambridge (CIE)Flashcards16. ThermodynamicsInternal Energy

Internal Energy (Cambridge (CIE) A Level Physics): Flashcards

Exam code: 9702

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FrontInternal energy
Define internal energy.
FrontInternal energy
State two ways the internal energy of a system can increase.
BackInternal energy
Doing work on it
Adding thermal energy to it (heating it)
FrontInternal energy
State two ways the internal energy of a system can decrease.
BackInternal energy
Losing thermal energy to its surroundings
The system doing work on the surroundings (e.g. a gas pushing a piston)

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Cards in this collection (7)

Define internal energy.
The internal energy of a system is the sum of the random distribution of kinetic and potential energies within a system of molecules.
State two ways the internal energy of a system can increase.
- Doing work on it
- Adding thermal energy to it (heating it)
State two ways the internal energy of a system can decrease.
- Losing thermal energy to its surroundings
- The system doing work on the surroundings (e.g. a gas pushing a piston)
The internal energy of a system is the sum of the random distribution of .......... and potential energies within a system of molecules.
The internal energy of a system is the sum of the random distribution of kinetic and potential energies within a system of molecules.
For an ideal gas, the change in internal energy ΔU is proportional to which quantity?
The change in temperature, ΔT (in kelvin):
$Δ U \propto Δ T$
True or False?
For an ideal gas heated from 50 °C to 150 °C, the internal energy triples.
False.
Internal energy is proportional to thermodynamic (kelvin) temperature, not the Celsius value. Converting to kelvin (323.15 K to 423.15 K) gives a ratio of only about 1.3, so the internal energy does not triple.
What is the total internal energy of an ideal gas equal to, and why?
The total kinetic energy of its molecules, since an ideal gas has zero potential energy.

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