Metals undergo linear, superficial and volumetric expansion when heated, what are the coefficients of expansion and how do we determine are explained in detail in this science animation

Most substances expand when heated and contract when cooled.
The change in length / area or volume (due to contracting/expanding) is directly related to temperature change. Every linear dimension increases by the same percentage with a change in temperature

Not all materials contract/expand at the same rate; the amount of contraction/expansion varies depending on the material. The coefficient of linear expansion, is a proportionality constant that determines the rate of change in length in different materials when they are heated and cooled.

Applications :
In thermometers, thermal expansion is used for measurement. Liquid expand more than solids. Stained red ethanol has a relatively large coefficient of cubic expansion than glass . Temperature can be measured as it rises through the capillary faster.

-If a lid of a glass jar is tight, holding it under hot water for a short time will make it easier to open. This is because the lid will be struck by the hot water more directly than the glass, and so it will expand sooner. Furthermore, metals generally expand more than glass for the same temperature change.

Problems:
- If steel bridge expand or contract, it can cause structural damage.
However, steel bridges are often mounted on rollers to prevent this problem.

-Expansion gaps also exist in train tracks.

-Water and steam pipes often have a U-bend in them to allow for thermal expansion.

• Application
  
  
•  Heat - Bi-metallic strip- thermostat
•  Heat -Effects-Thermal Expansion


• Properties
  
  
•  Heat Thermal equilibrium - Zeroth law
•  Heat and Temperature - Concept of heat
•  Heat and Temperature - Conductivity of materials
•  Heat and Temperature - Convection currents
•  Heat and Temperature - Kinetic theory of matter
•  Heat and Temperature - Thermometry