If your hands are wet and no towel is handy, you can remove some of the excess of water by shaking them. Why does this get rid of it?
Some water shakes off, but air flow on the skin greatly increases evaporation of the water.
When you shake your wet hands, the water droplets are flung off due to the centrifugal force generated by the shaking motion. This force causes the water droplets to move outward along a curved path away from your hands, effectively removing some of the excess water.
The process of shaking your hands to remove water involves a few key factors:
1. Centrifugal Force: When you shake your hands vigorously, the circular motion creates a centrifugal force. Centrifugal force refers to the apparent outward force experienced by an object moving in a curved path. In this case, the water droplets cling to your hands due to surface tension. As you shake your hands, the centrifugal force acts on the water droplets, pushing them away from your hands and causing them to be flung off.
2. Air Resistance: As the water droplets are thrown off your hands, they encounter air resistance. Air resistance works against the motion of objects passing through the air, and in this case, it acts as a hindrance to the water droplets' movement. The air resistance slows down the water droplets, causing them to lose momentum and eventually fall away from your hands.
3. Evaporation: Shaking your wet hands also increases the surface area of the water droplets, facilitating evaporation. As the water droplets become thinner, more surface area is exposed to the surrounding air, which enhances the rate of evaporation. As a result, some water from your wet hands is evaporated into the air, further reducing the amount of water on your hands.
It's important to note that shaking your hands will not completely dry them, especially in comparison to using a towel. However, it can be a helpful technique to remove some of the excess water when a towel is not readily available.