thermal expansion

Thermal expansion is the phenomenon where materials expand in size when heated and contract when cooled. This happens because the particles within the material move faster and spread apart as temperature rises. For example, metal railway tracks can bend in hot weather due to this expansion, and gaps are often left between sections to accommodate it. Conversely, when temperatures drop, materials shrink, which is important to consider in engineering and construction. Understanding thermal expansion helps prevent damage in structures and machinery by allowing for changes in size due to temperature fluctuations.