Eli5 how do water droplets work


No matter how much water there is a water droplet stays the same size. Is this something to do with gravity. Once the water droplet gats too heavy the is too much force for it to continue hanging and it falls. It’s just got me bamboozled.

In: 1

It’s to do with air.

If you have a droplet that’s too big, then it falling through the air will cause air resistance, making the droplet act like a parachute and balloon out. Except, water isn’t held together the way a parachute is, it’s only held together by the pretty weak bonds that cause surface tension, so the droplet just falls apart.

Water droplets form because of surface tension. Because of this, they can continue to suck up water and get bigger. You are correct that gravity affects water droplets. Surface tension keeps the droplet secure to a surface. When the mass of a droplet gets big enough, the gravity acting on it is more than the force of the surface tension.

>a water droplet stays the same size

Droplets do vary in size. What you mean is, if a droplet gets too big, the water has a tendency to split it into smaller droplets. This is always due to a combination of air resistance and gravity. What keeps a droplet or any mass of water together is surface tension. That’s the water molecule’s tendency to stick together. If disturbed by a greater force, that bond breaks down. Gravity is such a force, and so is air resistance.

The strength of the surface tension is only related to the type of liquid, so most water droplets will tend to have around the same size as opposed to liquids with different properties (molar mass, viscosity, etc).