Pressure
Through this experience, we will teach you sciencs behind drink with a straw.
How it works
It is the pressure that is at stake here. When your index finger closes off the top of the straw dipped in water and you withdraw the straw, you are creating pressure. Your finger prevents air pressure to increase in the straw. That is to say, above the water content in the straw, there is a little air, and below, there is all the air of the room! And the air puts pressure on everything around you.
When you suck water through a straw, first your mouth closes around the end of the straw and secondly you suck air into the top of the straw. The pressure becomes even stronger underneath, thus raising the water!
Equipment required
- Transparent straw
- A glass of colored water
How do the experiment
- Glass of colored water.
- Plunge a straw in the glass and removes it.
- You notice that the straw is empty now.
- Now again plunge the straw in water.
- Place finger on top of mouth of the straw.
- Remove gently from glass without moving your finger.
- You will notice that the water stays in the straw.
- Take off your thumb, and the water flows again!
