Physics · Ch 8 — Heat and Thermodynamics
Thermal Expansion of Solids, Liquids and Gases
Thermal Expansion of Solids, Liquids and Gases
Thermal expansion is the tendency of matter to grow in length, area or volume as its temperature rises; gases expand the most (negligible intermolecular forces), then liquids (weaker forces than solids), then solids the least (atoms simply vibrate with larger amplitude about fixed lattice points). Three coefficients quantify this for a small temperature change : linear expansion , area expansion , and volume expansion , all with SI unit °C⁻¹ (or K⁻¹); for the same specimen, and . Real consequences include railway-track expansion gaps that prevent buckling in summer heat (Figure 8.3, and worked in Example 8.6 for the Eiffel Tower), a tight glass-bottle lid loosening in hot water ( …
What this figure shows. A photograph-style illustration of a railway track or bridge fitted with a visible small gap (an expansion joint) between consecutive sections of rail or roadway. The gap exists specifically so that when the metal expands in the summer heat, the sections have room to lengthen without buckling, warping or pushing against each other; if the gap were absent, thermal expansion of the rails in hot weather could phys …
What this figure shows. Three side-by-side diagrams labelled (a), (b) and (c). Diagram (a), linear expansion, shows a rod of original length L0 at temperature T0 growing to a longer length L at a higher temperature T = T0+ΔT. Diagram (b), area expansion, shows a flat shape of original area A0 growing uniformly to a larger area A at the higher temperature. Diagram (c), volume expansion, shows a solid block of original volume V0 growing uniformly to a larger volume V at the higher temperature. All three diagrams use dashed outlines for the original size and solid outlines for the expanded size, visually motivating why the same underlying physical effect is described by three different coe …