Activity Overview
Give the Strainer Full of Water experiment a try and get an intriguing lesson in surface tension. Is it even possible for a liquid such as water not to pour through a strainer? Try this experiment and test your hypothesis.
Materials Needed
- Small wire strainer
- Empty Bowl
- A glass of water
- Cooking Oil
How to do it
- Coat the strainer with cooling oil. A good way to accomplish this is to pour the oil into the bowl and gently slosh the oil around in the bowl until it is thoroughly coated with oil.
- Shake the strainer carefully into the bowl so that all of the holes in the strainer are open. There is no need to throw the oil away in this experiment, you can still use it to bake or even fro another experiment.
- Hold the strainer over the sink and start pouring water at a very very slow rate from the glass into the strainer.
- As you meticulously pour the water , you will see that the strainer begins to fill with water. If you look very closely, you will see that tiny beads of water protruding through the strainer but very few will actually push through and leak out.
Scientific Explanation
It is actually the surface tension of the beads of water that makes this experiment work. The oil helps a bit by coating the wires with a smooth coating, while also making the spaces between the wires slightly smaller than before.
