THERMAL EXPANSION
The linear expansion of a heated solid or liquid can be measured by a quantity a, the coefficient of linear expansion. This coefficient is defined in such a way that it measures the percentage change in the length per degree temperature change.
a = Coefficient of linear expansion (SI: 1/ oC)
DL = Change in length (SI: m)
DT = Change in Temperature (SI: oC)
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Coefficients of Thermal Expansion at 20 oC
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Substance
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Linear Coefficient
a (1/ oC)
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Volumetric Coeff.
b = 3a (1/ oC)
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Aluminum
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24 x 10 -6
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72 x 10 -6
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Brass
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19 x 10 -6
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57 x 10 -6
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Copper
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17 x 10 -6
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51 x 10 -6
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Glass (ordinary)
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9 x 10 -6
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27 x 10 -6
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Glass (Pyrex)
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3 x 10 -6
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9 x 10 -6
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Iron/Steel
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12 x 10 -6
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36 x 10 -6
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Lead
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29 x 10 -6
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87 x 10 -6
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Ice
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51 x 10 -6
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153 x 10 -6
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Gasoline
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950 x 10 -6
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Mercury
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180 x 10 -6
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Water
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210 x 10 -6
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Thermal Expansion of Volume:
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Thermal Expansion of Area:
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