Learning Goal:

To understand thermal linear expansion in solid materials.

Most materials expand when their temperatures increase. Such thermal expansion, which is explained by the increase in the average distance between the constituent molecules, plays an important role in engineering. In fact, as the temperature increases or decreases, the changes in the dimensions of various parts of bridges, machines, etc., may be significant enough to cause trouble if not taken into account. That is why power lines are always sagging and parts

Part A

A square is cut out of a copper sheet. The square is heated uniformly. As a result, it turns into

a square with a larger area

a square with a smaller area

a rectangle with a larger area

a rectangle with a smaller area