Why does a hot, dry towel dry faster than a cool towel?

Why does a hot, dry towel dry faster than a cool towel?

• A. Cooler air can hold more moisture, increasing evaporation rate.
• B. Warmer air has no effect on evaporation.
• C. Evaporation speed depends only on humidity.
• D. Warmer air can hold more moisture, increasing evaporation rate.

Answer: (D)

Warm air can hold more water vapor than cool air, so the surrounding air has a larger capacity to accept water that evaporates from the towel. Water molecules at the towel’s surface gain energy and escape into the air; because the air is warm and dry, it isn’t near saturation, so it can take in a lot of that vapor, creating a strong driving force for evaporation. The result is a faster drying towel. If the air were humid, evaporation wouldn’t be as quick even if it’s warm, because the air is closer to saturation.

Warm air can hold more water vapor than cool air, so the surrounding air has a larger capacity to accept water that evaporates from the towel. Water molecules at the towel’s surface gain energy and escape into the air; because the air is warm and dry, it isn’t near saturation, so it can take in a lot of that vapor, creating a strong driving force for evaporation. The result is a faster drying towel. If the air were humid, evaporation wouldn’t be as quick even if it’s warm, because the air is closer to saturation.