- #1
duran9987
- 12
- 2
I just began reading Feynman lectures and it turns out that during evaporation, water molecules that move faster than average (higher temp) break away from the attraction of their neighbors leaving behind molecules that move slower than average (lower temp) and result in a cooler liquid. When a vapor molecule gets close to the surface of the water, its speed is increased by the attraction of molecules in the water and thus re-introduces heat to the liquid. By this logic, Feynman says that by blowing on soup (blowing away moist air filled with vapor molecules, and introducing dryer air) causes the soup to cool down faster. Can someone explain to me why blowing on the soup, or any liquid, wouldn't just increase the temperature due to increasing the speed of molecules on the surface (liquid moves with you blow on it) ? Or wouldn't it keep the surface hot and maintain continuous evaporation before a drop in temperature?