Material Required:

For this experiment, we need 6 things.

1. A Plastic container.
2. A paper strip.
3. A screwdriver.
4. A candle
5. A matchbox
6. Coloured water

Let's get started!

Conducting the Experiment:

1. Begin with the plastic container. Punch 3 holes of the exact same size at different heights. We are making the holes diagonally so that the water flow from the 3 holes do not interfere.
2. Place this plastic container at some height inside a tray. I’m using a block for this purpose.
   
3. Pour the coloured water into the container and your fountain is ready. Ah! Notice something interesting.
4. The water is flowing out of each hole differently. Why does this happen?

Scientific Principle and Application

Question: 1. Why did the water flow out differently from each hole?

Now I know what you might be thinking, - the water flows out differently from each hole because the holes have been made at different heights.

But how does the height of the holes affect the pressure of water?

If you look carefully, you’ll see that the water from the bottom most hole comes out with so much pressure and reaches the farthest.

This happens because the weight of all water above the bottom most hole puts pressure on the layer of water below.

This shows us more water equals to more pressure. Moving up to center hole, because there is lesser water above the center hole , the water comes out with lesser pressure from the center hole than the bottom most hole.

This shows us that the pressure is the lowest at the top and highest at the bottom. Hence, proven water pressure increases with depth.

If water pressure increases with depth, imagine how much pressure would our little starfish feel with all the weight of the ocean water above it. Well starfishes can survive as deep as 20,000 ft and so they feel approximately 600 times more pressure than you and I on the surface.

600 times!! Well, I don’t think I’m going to dive that deep. I maybe a star scientist but I am no starfish you see Because I can dive that deep. But it would break all my bones. Oh! No wonder, starfishes don't have bones.

So now you see why deep sea creatures like Octopus and Starfish don't have bones. Because they have to deal with so much water pressure. From this experiment we know water has pressure.