We know that many materials swell when heated and contract when cooled. The part of Physics that studies this behavior of bodies is called Thermology. In the study of Thermology, we saw that when we heat a certain material, there is an increase in the thermal agitation of its molecules. This increase also causes an increase in the distance between them, thus, when they distance themselves, there is a dilation of the body.
We also saw that dilation can occur in three ways: linear, superficial and volumetric. This article aims to study the volumetric expansion of solid objects. The main characteristic of the volumetric expansion of solids is that it occurs in all dimensions, that is, there is variation in length, width and height. See the illustration above, where, when heated, a metal bar has its dimensions increased.
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Through reasoning similar to what is done in superficial dilation, we can show that volumetric dilation ΔV = V - V0 of a body, when its temperature is increased ΔT = T - T0, is given by:
ΔV= γ .V0 .ΔT
Or equivalently V = V0 (1+ γ.ΔT), where V0 is the volume at temperature T0, V is the volume at temperature T and γ is the volumetric expansion coefficient, such that:
γ=3α
Remembering that α is the coefficient of linear expansion.
In SI the units are m3 for volume, K-1 for the coefficient of volumetric expansion and K for the temperature.
By Domitiano Marques
Graduated in Physics
Would you like to reference this text in a school or academic work? Look:
SILVA, Domitiano Correa Marques da. "Volometric Dilation of Solids"; Brazil School. Available in: https://brasilescola.uol.com.br/fisica/dilatacao-volumetrica-dos-solidos.htm. Accessed on June 27, 2021.
