Engineering
Intermediate

Linear Thermal Expansion

Change in length due to temperature change.

Formula

ΔL=αL0ΔT\Delta L = \alpha L_0 \Delta T

Variables

\alphaExpansion coefficient
L_0Original length
\Delta TTemp change

Example

A 10 m steel rail (α≈12×10⁻⁶) warmed 30 °C grows about 3.6 mm.

Did You Know?

Bridges have expansion joints because steel grows measurably longer on a hot day.

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