Question

A circular piece is cut from a flat metal sheet. The sheet is, then, placed in a furnace. Will the size of hole become larger or smaller? Explain.

Answer 1

Wherever we heat a substance the molecule inside the substance acquires the kinetic energy and they try to move from its place and as a result, the substance gets expanded. The ratio of the increase of area, volume of a body, or length per degree rise in temperature to its area, volume, or length, respectively, at some specified temperature, the pressure is kept constant, is known as the coefficient of expansion.

Complete answer:
If a circular piece of metal is cut from a flat metal sheet and then the sheet is placed in a furnace the size of the hole from which the circular piece is cut will become larger. Because whenever we heat any metal sheet it expands.

Additional Information:
This same process is used to attach a metal ring to a cart at first the ring is heated red hot and then it is slid over the wooden wheel of the cart then it is allowed to cool down, water is not applied to cool it down because it cold waterfalls on the metal rim then it has chances of cracking or bending resulting in an accident when the cart will be used.

Note:
The metal piece can withstand heat up to a limit only if that limit is crossed then it melts resulting in loss of material. This melting is also a process of expansion of molecules due to heat as the solid body has got enough kinetic energy it now tends to flow and acquires the property of liquid till the heat is inside the body.