Find how much a material lengthens when heated.
Most materials expand when heated and contract when cooled, because their atoms vibrate more strongly at higher temperatures and push each other apart. For a long, thin object the change in length is ΔL = αL₀ΔT, where α is the coefficient of linear expansion, L₀ the original length, and ΔT the temperature change.
Even small expansions are important in engineering. Bridges include expansion joints, railway tracks leave gaps, and pipes are designed to flex, all to accommodate thermal expansion. Steel has a coefficient of about 1.2 × 10⁻⁵ per kelvin. Enter the original length, the coefficient, and the temperature change to find the change in length and the new total length.
Expansion joints leave room for the bridge to lengthen in hot weather. Without them, thermal stress could buckle or crack the structure.
No. Each material has its own expansion coefficient. Metals generally expand more than glass or ceramics for the same temperature rise.