Chapter 13, Problem 62A

To determine

Covering the hiking canteen with wet canvas bags cools down the water in canteen is to be explained.

Explanation of Solution

Introduction: It takes energy to vaporize the water in the canvas bag.  The energy comes from the water in the canteen, thus cooling it.

Hiking canteens used by hikers are covered with wet canvas bags as the water starts to evaporate into the atmosphere that leads in absorption of energy and the water inside the canteen. As a result, there is a drop in temperature of the canteen and water due to decrease in heat.

Conclusion:The water on the canvas bag evaporates and absorbs energy and water inside the canteen which lowers the temperature of the canteen and water.