Answer:
The evaporation rate is an important factor that influences the evaporative cooling effect of permeable pavements. Liquids change into vapor by the process of evaporation. The factors that affect the rate of evaporation of liquids are temperature, surface area, wind speed, and humidity. Evaporation causes cooling is the general process. The principle involved here is the matter must either gain or lose energy to change its state.
Explanation:
In a desert cooler, the water inside it is made to evaporate. This leads to the absorption of energy from the surroundings, thereby cooling the surroundings. Evaporation depends on the amount of water vapor present in the air (humidity). If the amount of water vapor present in the air is less, then evaporation is more. On a hot dry day, the amount of water vapor present in the air is less. Thus, water present inside the desert cooler evaporates more, thereby cooling the surroundings more. That is why a desert cooler cools better on a hot dry day.
