Investigating air pressure – more eggs!

Today we are looking at air pressure with this fun air pressure investigation.

Air pressure is the force exerted by air on any surface in contact with it.

We are going to demonstrate air pressure by using it to force an egg into a bottle.

Air Pressure Investigation

What you need:

A boiled egg

A glass bottle or jar with a neck a little smaller than an egg

2 matches

What to do:

  • Place the cooled boiled egg on top of the glass bottle, making sure there is no way the egg fits through.

air pressure investigation

  • Ask an adult to light two matches and drop them inside the glass jar, quickly place the egg back on top.
  • Watch as the egg drops inside the jar.


The Science Bit

The matches heat up the air inside the glass jar. The air then expands and some escapes out of the jar. Once the matches go out, the air starts to cool, making the pressure drop. The air outside the jar now has a higher pressure than the inside, and forces its way inside the jar, forcing the egg downwards as it does so.

Our jar was quite small, so it would be interesting to see what would happen if a larger one was used. If you try please let us know!

Don’t forget to check out our other air pressure experiments for kids.

 

 

 

 

 

 

 

There are 45 comments

  1. maggy, red ted art

    Ooh very clever… does take me back to science days.. I would have tipped on that there is “less air” in the jar once the fire has “consumed it”… thus lower pressure. Need to scrubbed up my physics. Makes me have a good think again!

    Thank you for linking to kids (&mums) get crafty!

    Maggy

      1. melissa

        Quick question you stated that the air had less pressure because of a warming/cooling, expansion/contraction reaction. I was under the reasoning that the air pressure was less was because you removed the air and created a vacuum in the container. Since fire consumes oxygen, the fire from the match consumes the oxygen creating a vacuum, the suction effect.

  2. Kayren

    with a larger jar it should suck the egg down into the bottom of it- did this with my kids in 8th grade science class and it never ceases to amaze them (me too)

  3. Andy

    To get the egg out all you need to do is create a higher pressure inside the container. This can be done by holding it upside down and blowing air into it. Since it’s upside down the egg will act as a plug when you stop blowing. With the higher pressure inside of the container now, the egg should pop out.

  4. joyce

    we did this with a balloon filled with water – eggs are a bit too precious over here – and it worked beautifully

  5. M Maggart

    You can also use a small hollow rubber ball it acts like the egg but doesn’t break up. Rinse out the burnt material and ” blow ” the ball out of the jar( same way it got in) Blowing into the jar makes the air inside at a greater pressure than the air outside and the ball pops out. Make sure you tilt the jar uoside down so the ball comes down to the neck when you blow into the jar and it pops out.

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