Physics Why do you use a hair dryer to blow hot air to dry your hair faster?

Because the speed of evaporation is related to the temperature of the liquid, the evaporation area and the speed of air flow on the liquid surface.

The higher the temperature, the faster the evaporation; the larger the evaporation area, the faster the evaporation; the faster the air flow, the faster the evaporation.

A hair dryer can increase the temperature of the water in the hair and speed up the air flow, so it can speed up the evaporation of water.