Imagine having hundreds of kilograms of weight on your body. Well, we do! We just don’t realise that air has weight. Â It is all to do with the fact that air has something called mass and is pulled down to Earth by gravity and therefore it has weight.
This experiment shows you just how heavy air can be. Give it a try!
Materials
- Smooth table
- wooden ruler (cheap)
- Safety goggles and gloves
- large sheets of newspaper
Remember:
- Wear safety goggles and gloves
- Make sure you are swinging your arm away from near-by furniture and people.
- Use a thin / cheap ruler. You don’t want to be Hercules and try a plank of wood! That would break your hand. ONLY use a 30cm cheap ruler.
Place the safety goggles over your eyes.
Fold the newspaper several times and then smooth it on top of a bench so that there is no big ‘bulges’ of air under the paper.
Place the ruler in the middle of the paper and spread the paper over the table so that there is NO air bubbles. Really flatten out the newspaper. Now, muster up your ‘Karate-kid’ powers and give it a chopping action (while wearing your goggles and glove). Is there a difference in the outcome?
The evidence is clear, AIR is POWERFUL.
Watch the episodes below and give it a try. Find out ‘What’s Going On?’ by watching the ‘Looney Lab’ episode. Have FUN and remember science is like MAGIC!
Air is a powerful substance. If you have traveled in a plane, you may have marveled at its ability to lift a 400 tonne plane into the air. (World record is lifting a 600 tonne plane into the air… Antonov An-225).
Everything that has mass also has weight. Air is made up of lots of small invisible particles called molecules. These molecules are nitrogen gas, oxygen gas and others. They extend from the ground up to the top part of our atmosphere.
If you can add up the weight of all the molecules above 1cm square you should get approx 1kg.
This means that the air above the newspaper has (depending on its size) 100’s of kg of weight on it.
When you hit the ruler, the weight of air on the paper stops the ruler from being pushed upwards. The ruler breaks!
Science ‘Magic’ at work!
If you would like
– more details,
– pictures of the second half of the experiment
– information on how to investigate this further
– links to everyday examples
After doing this experiment, why not checkout some more pressure concepts (after doing more wacky experiments on our website….of course!)
Air Pressure Explain Youtube clip
Pressure: Is a measure of how much force is applied on a surface and is related to the size (area) of the surface. Here, the size of paper can be used to calculate how much pressure is on the paper. If you like maths, check out this formula for how to calculate pressure.
Mass: Is a measure of how much ‘stuff’ (or matter / atoms/particles) an object has. It is measured in the units g/kg etc. This term is often confused with weight. See this website to see the difference.
Weight: Is a measure of how much the pull of gravity attracts a body towards the Earth and is measured in a unit called Newtons.
Force:Is a twist, pull or push. Here, the Earths gravitational pull is pulling the air downwards and causes its weight to impart a force on the paper.