Final answer:
On a warm day, a glass of plain ice-cold water without ice will warm up faster compared to a glass of ice water with ice. The ice in the glass of ice water slows down the warming process as it gradually melts, keeping the water at a lower temperature for a longer period of time.
Step-by-step explanation:
When comparing a glass of plain ice-cold water without ice to a glass of ice water with ice, the ice-cold water will warm up faster on a warm day. This is because the ice in the glass of ice water slows down the warming process. Ice requires a large amount of energy to melt, and as the ice absorbs heat from the surroundings, it melts gradually, keeping the water at a lower temperature for a longer period of time.