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
96 exam-style questions on CIE IGCSE Physics 2.2.1 Thermal expansion of solids, liquids and gases. Each one has a worked solution and a mark scheme showing where the marks go.