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The Archimedes’ Principle: Try This Experiment At Home!

Try this experiment at home to learn about the Archimedes' Principle

bouey floating in water

Photo: Curran Kelleher (flickr)

The law of buoyancy, nowadays called "Archimedes' Principle", was discovered by Archimedes.

The Greek philosopher-scientist Archimedes is famous for sitting down in the tub one day and then running naked through the streets of Athens shouting “Eureka!”

But what had he discovered?

Archimedes’ Principle

It was the law of buoyancy, nowadays called “Archimedes’ Principle.” And you can demonstrate it yourself without even running around naked.

Try It At Home Experiment:

Here’s how. You’ll need one of those small kitchen scales. You’ll also need a pie pan, a glass, and something small that floats, like a small block of wood.

Weigh the block of wood on the scale. Then remove the wood and place the pie pan on the scale.

Write down the weight of the pie pan too. Now fill the glass entirely to the top with water and place it carefully inside the pie pan. Take the small wooden block and put it in the glass too. This will cause some of the water to spill out of the glass and into the pie pan.

Next, remove the glass altogether, being careful not to spill any more. Now you just have a pie pan with spilled water in it.

By subtracting the weight of the pie pan from the weight of the pan with spilled water in it, you get the weight of the spilled water alone. And guess what? If you were careful, the spilled water will weigh exactly as much as the block of wood!

A Great Principle

This is Archimedes’ Principle. An object will float if it displaces as much water as it weighs. This is true for any object –even huge, iron battleships!

  • John Phillips

    This seems like the perfect test to get younger kids interested in the most basic of sciences. I remember most of my interest in science came from two particular elementary teachers that could cause wonder amongst myself and my peers with simple experiments that at the time practically seemed like magic.

  • Pranav Dange

     If glass of water has an ice cube floating in water. The water lelel just touches the rim of the glass. Will the water overflow when the ice melts. Give reason. 


    WOW! This was a great website! I learned so much! I will try this with my class and see what the results are.


    Hello, thank you for this wonderful website. It helped me very much. Goodbye, Thank you!!!!!! i’ll try this with my mom tomoorwww thanks for wasting my timeeeee.


    Well, this stank. I wanted to show my kids (I have 18) and it did NOT work. Thank you for dissipointing me.

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