Answer
When we run the lid of a jar under hot water, the metal lid will expand due to thermal expansion. As the metal lid expands, the lid becomes looser on the jar so it is easier to get the lid off the jar.
Work Step by Step
When we run the lid of a jar under hot water, the metal lid will expand due to thermal expansion. As the metal lid expands, the lid becomes looser on the jar so it is easier to get the lid off the jar.
Even if the glass part of the jar under the lid expands, the coefficient of thermal expansion of glass is less than the thermal expansion of metals, so the metal lid will expand by a greater factor than the glass bottle.
