Question

How does pouring hot water over a metal lid on a glass jar make it easier to open the jar?

Answer 1

• Metals usually expand or contract on the action of heat.
• When hot water is poured, the metal will expand much easier than the glass.
• As, a result a gap will be formed between the glass jar and the metal lid.
• This gap increases as the metal lid expand and the lid will pop out from the jar.
• So it is easy to remove a metal lid from a glass jar by pouring hot water.