When cold water is poured on a can containing hot water, the can collapses because the
Answer Details
When hot water is kept in a can and cold water is poured over it, the can collapses because of the difference in temperature of the hot water inside the can and the cold water outside the can. The metal of the can contracts due to the cooling of the hot water inside. As a result, the pressure inside the can decreases, and the external air pressure becomes greater than the pressure inside the can. This causes the can to collapse inward. Therefore, the correct option is "external pressure becomes greater than the pressure within the can."