Why are small gaps (expansion joints) left between the sections of a concrete road bridge?
to allow for expansion of the concrete sections on a hot day
to allow for contraction of the concrete sections on a hot day
to allow for expansion of the concrete sections on a cold day
to allow for contraction of the concrete sections on a cold day
528 exam-style questions on CIE IGCSE Physics 2.2 Thermal properties and temperature, covering 2.2.1 Thermal expansion of solids, liquids and gases, 2.2.2a Internal energy and temperature, 2.2.2b Specific heat capacity, 2.2.3a Melting, boiling, condensation and solidification, 2.2.3b Evaporation, and 2.2.3c Cooling by evaporation. Each one has a worked solution and a mark scheme showing where the marks go.