# WATER EXPERIMENTS...?Can you please list a few water usage experiments? thnx..

scorpio37 | Student

Experiment 1 Diffusion is the process by which two liquids or gases mix.

It is caused by random molecular motion. The molecules in the water are moving around randomly and hit the molecules of the food dye. Gradually the food dye molecules move throughout the water. If you leave the glass for long enough, the food dye will have dispersed throughout the liquid.

Here is a good example showing the effects of these types of science experiments with water :

Additional science experiments with water for question 1 :

Try dropping a drop into the center after you have stirred the water. If you stir the water, then the water molecules are not moving randomly, and the food dye is seen to be dispersed in a spiral. When the water is stirred, what is the shape of the water surface? Concave as you look at it – higher at the sides, lower in the middle. This is a whirlpool or vortex. The water is moving much faster at the center of the whirlpool, so it has a lower pressure than the water at the edge (Bernoulli's Principle). Therefore the pressure from the atmosphere depresses the water more in the center than at the edge. What happens if you put some tea leaves into the water, stir it and then take the spoon out?  When the tea is being stirred, the tea leaves are in a ring towards the outside of the cup. After the spoon is taken out, the tea leaves move to the center at the bottom of the glass. You might expect the tea leaves to stay on the outside of the cup (like in a centrifuge or the force you feel on a roundabout), however this is not the case. In fact it was Albert Einstein who explained this paradox. A secondary flow is setup in the water due to friction between the water and the base of the cup, which means it is moving slower. Therefore water at the top of the glass moves outwards, and then down the side of the glass and back to the middle at the bottom before rising to the top in the center. The tea leaves move to the bottom at the center, but are too heavy to rise with the water, so stay there.

Experiment 2

Water is able to maintain a convex (domed) surface due to surface tension. Eventually the force due to the weight of the water is greater than the surface tension and the water will spill over the sides of the penny.

If you are careful, you can also overfill a glass - that is, get the level of the water to rise higher than the level of the glass.

Experiment 3

The detergent reduces the surface tension of the water, so a smaller force (less weight of water) is required to break it.

Experiment 4

If you use metric measures, one litre of water weighs 1 kg (or 1 millilitre wieghs 1 g).

Experiment 5

The soils that stick together more will resist erosion better. Planting trees reduces erosion, as the soil can bind to the roots.

Archimedes Principle states that when an object is placed in a liquid the upward force (buoyancy) is equal to the weight of the water displaced by the object. When an object floats the upward force must equal the downward force, which is the weight of the object. Therefore when the liquid is denser, less liquid is required to create the bouyancy, so the apple floats higher in a denser liquid.