To understand the effect of temperature on water flow and the formation of convention currents in water.
- Food coloring
- Eye dropper
- Two ice cubes
- Warm tap water
- Marking tape
- One liter small-mouth jar
- 15O ml paper cup
- Using the pencil pierce four small holes near the bottom of the paper cup. Make sure the holes are evenly spaced evenly around the cup.
- Place the paper cup in such a way the rim of the cup rests on the mouth of the jar.
- Stick a tape on the outer portion of the jar to make a spot at a point 1 cm above the holes.
- Take the cup out, and fill the jar with warm water till the spot marked.
- Put the paper cup back into the jar and drop two ice cubes in the cup.
- Wait for 2 minutes
- To the water in the paper cup add 4 drops of food color.
As the water leaves the cup, it begins to twist and curl as moves down through the warm water. The reason for this trend is the fact that as warm water enters the cup it is cooled by the ice cubes. The warm water in the jar expands and the cold water in the cup contracts. The density of the cold water is higher than that of warm water and hence sinks through the warm water. This movement of water due to the variation in temperature is called convention currents.