Question

How does thermal expansion affect bridges?

Answer 1

Hint: We need to know what is thermal expansion and study this using the example of bridges. Thermal expansion is the tendency of matter to change its dimensions in response to a change in temperature. It applies to all solids, liquids and gases. Thermal expansion can affect bridges by either expanding or contracting the bridge depending on the temperature.

Complete step by step answer:
We know that thermal expansion can affect bridges by either expanding or contracting the bridge. If the temperature is too high, it is likely to distort the bridge. If a bridge gets very heated with the increase in temperature, the road bed will expand and when it gets cooled it gets contracted. These changes initially may seem sparingly small or almost invisible, but with constant temperature changes, the bridge length will undergo very prominent changes. In regions with extremely high temperatures, the bridges are likely to get distorted with time. This phenomenon can be compared to the expansion of a rubber band where the continued expansion and contraction eventually causes the band to tear off.
The reason behind this phenomenon is that temperature increases the energy of the particles which make up the bridge and when this energy increases, the particles start moving faster and faster weakening the intermolecular forces between them, therefore expanding the substance. There exists a coefficient of thermal expansion which describes how the size of an object changes with a change in temperature.

Note:
It must be noted that one remedy to this problem is the usage of expansion joints which fill gaps within the bridge and act as a flexible, variable filler that help the bridge adapt to temperature changes without distorting.