HEAT
MYP-5
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Thermal Expansion happens a lot in everyday life. When something is heated and expands this is Thermal Expansion. The way Thermal Expansion works, is when it is heated the atoms expand, and then when it is cooled it shrinks. Several examples of Thermal expansion is the tendency of matter to change in volume in response to a change in temperature. When a substance is heated, its particles begin moving more and thus usually maintain a greater average separation. Materials which contract with increasing temperature are rare; this effect is limited in size, and only occurs within limited temperature ranges.
Bridges and other structures have expansion joints (there are gaps in the road, which you hear/feel when crossing them in a car for example - usually in both ends of the bridge and sometimes in between as well, depending on the lenght of the bridge).
Sidewalks - depends on the material of the sidewalk (sometimes there may be some spaces between different sections, but the temperature fluctuations are not so huge that it is reasonable to use any predicament against TE.
Railroads - do you know the banging sound really associated with trains and railroad? This is a basic example of thermal expansion compensation. The tracks are assembled so that the ends of two track sections are not touching each other. The gap in between allows the track to expand in heat (therefore the sound of train wheels rattling is louder in the winter when the gaps are bigger and less in the summer)
Electric Lines-thermal expansion in a solid is the sagging of electrical power lines on a hot day. This happens because heat causes them to expand, and, thus, there is a greater length of power line extending from pole to pole than under lower temperature conditions. It is highly unlikely, of course, that the heat of summer could be so great as to pose a danger of power lines breaking; on the other hand, heat can create a serious threat with