# Internal Energy and Temperature

Physics
Temperature and Internal Energy

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• Created by: Steven
• Created on: 11-04-11 16:09

## Temperature

Temperature is the measure of the degree of heat of an object.

It has two scales:

Celcius (Degrees Celcius [DC])
Absolute (Kelvin [k])

Both scales are defined by set points of temperature.

Celcius Scale is defined by;

0DC - Melting Point of Pure Ice
100DC - Steam Point

Absolute Scale is defined by

273.16K - Water Triple Point (Point at which it can exist in three major states)

-273DC = 0K

Note: When working in AQA Physics A, ALL thermal energy questions must be answered using the Absolute scale, though values of temperature will often be given in the Celcius scale.

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## Internal Energy

Energy Transfer only occurs when;

One object does work on another
There is a temperature difference between the two objects. This happens by;
Conductions
Convection

Internal Energy is the measure of the measure of the molecular energy with relation to movement and position. It can change when;

Work is done on or by the object
During Energy Transfer

Thermal Energy is a measure of molecular energy due to temperature.

Temperature is not the only source for internal energy. A magnatised iron core has a higher internal energy than a non magnatised iron core. The internal energy of an object is the sum of the random distribution of the kinetic energy and potential energy of its molecules.

-273DC = 0K

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