What is the idea of Thermal Expansion?

1 Answer
Oct 15, 2017

See below.

Explanation:

The idea of thermal expansion is that a material can change in shape/area/volume in response to a change in temperature.

There are three general types of thermal expansion: linear, area, and volume.

  • Linear  expansion:

color(blue)((DeltaL)/L_0=alphaDeltaT)

Where:

  • L_0 is the original length of the material
  • DeltaL is the change in length (making (DeltaL)/L_0 the fractional change in length)
  • alpha is the expansion coefficient (depends on specific material), and
  • DeltaT is the temperature change experienced by the material

Phy 218 Review Notes - Prof. Ekey (original source unknown)Phy 218 Review Notes - Prof. Ekey (original source unknown)

  • Area expansion:

color(red)((DeltaA)/A_0=2alphaDeltaT)

  • Where (DeltaA)/A_0 is the fractional change in area 

  • Every linear dimension increases by the same percentage with a change in temperature.

Phy 218 Review Notes - Prof. Ekey (original source unknown)Phy 218 Review Notes - Prof. Ekey (original source unknown)

  • Volume expansion:

color(purple)((DeltaV)/V_0=3alphaDeltaT)

  • Where (DeltaV)/V_0 is the fractional change in volume

Phy 218 Review Notes - Prof. Ekey (original source unknown)Phy 218 Review Notes - Prof. Ekey (original source unknown)