Air can apply pressure

Answer 1

As we know air is everywhere and we can't survive without air. It consists of various gases, dust particles, water vapors, etc. Air exerts a particular pressure on every single thing. Air pressure is calculated with the help of an instrument called barometer and according to it, the Earth's atmospheric pressure is 14.7 psi (pounds per square inch). We can't feel this pressure because it is everywhere. But if we are in a vacuum or in outer space where there is no air we have to use pressurized suits to protect our body. This is the reason why astronauts wear space suits. Here we are going to take a look at some air pressure experiments which will prove the existence of air pressure and will show that it has weight too.

Interesting Experiments to Measure Air Pressure

The experiments given below are easy to perform and need few things which are easily available at home. These air experiments for kids should be performed under the supervision of elders. Kids can also use these experiments as their physics projects.

Marshmallows Experiment

Take a glass jar and empty it completely. Add small pieces of marshmallows inside the jar and seal it with a wine vacuum cork. Attach a manual pump over the cork and try to pump as much air out of the jar as you can. This will make the marshmallows pieces swell and you will observe them growing. Now break the seal. As soon as the seal breaks and air comes rushing inside the jar, the marshmallows cramp down and return to its old size.

Water Glass Experiment

This is one of the best experiments to measure air pressure. Take a glass and fill one-third of it with water. Place a cardboard over the mouth of the glass. The cardboard should be bit bigger than the glass' mouth. Now apply some pressure on the cardboard from the left hand and invert the glass with the right hand. Slowly remove the hand and see what happens. The water does not fall from the glass, retaining the cardboard and the water in the same place as before. This takes place because the air pressure outside, i.e., 14.7 psi, is heavier than the combined weight of water and air inside the glass.

Balloon Experiment

This experiment with balloon will show you what air pressure can do. Take a balloon and blow it. Now stretch the mouth of the balloon, pinching the ends of the mouth so that you can hear a loud squeaking noise. You can also alter this sound and pitch. But the question is why a balloon makes such sounds? The reason for it is air pressure. When you stretch its mouth it leaves very little space for the air to come out. So because of the air pressure the mouth of the balloon vibrates which makes such sound. Ask someone else to perform this experiment so that you can touch below the mouth of the balloon and feel the vibration.

Egg Experiment

Take a hard-boiled egg and remove its shell. Take a bottle whose mouth is large enough to squeeze the egg inside it without squashing it but should also not easily allow the egg to enter the bottle. Now light a matchstick put it inside the bottle and immediately close its mouth with the egg. The match stick will utilize the oxygen inside the bottle and will create a low air pressure. High pressure outside the bottle will push the egg inside. This experiment with the air pressure shows how strong it can be.

Paper Experiment

Take a sheet of paper and hold the edges near to your lips. Place it at the bottom of your lips and try to blow hard. You may have to put the paper in different places to find the exact position. Now when you blow it the paper will fly up. This is because of air pressure. As you blow from the upper side of the paper it creates an area of low pressure above the paper and high pressure at the bottom of the paper. This high pressure forces it to fly in an upward direction. By this concept you can understand how do airplanes fly. They reach the height only because of air pressure.

Ping Pong Experiment

For this experiment, you will need a ping pong ball and a funnel. Place the ball in the funnel, and hold it in such a way that the wider part faces the ceiling. Now tilt your head and blow into the funnel. No matter how hard you blow the ball remains in the funnel without falling out. This happens due to the fact that the air blown at high speed decreases the pressure in the funnel. The outer air pressure also pushes the ball. Reduction in pressure inside the funnel and push from external pressure make the ball remain inside the funnel.

I hope you had a good time reading such simple, interesting and useful experiments to prove the air pressure around us. These air pressure experiments are basically for kids but elders can also enjoy doing it at home. So, try them and yes do let me know about your experiences.

Answer 2

Yes as in a tire. It's measured in pounds per sq. inch or psi.