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By Ruth Barnard

Make your own quick spinning top out of an old cereal box and learn

about the science behind the spin!

 

     

What you need:

• Old cereal box

• Toothpicks and/or pencils

• Scissors

• Compass (for drawing a circle and making a hole)

 

What to do:

1. Draw a circle on the inside of an old cereal box with your compass (about a 4cm radius)

2. Poke a hole in the centre with the point of your compass (there should already be a mark there from the compass)

3. Cut out your circle disc

4. Draw an ‘X' shape onto it with a ruler leaving you with four equal sections

5. Colour your sections in alternate colours (these colours will blend as it spins)

 


 
     

 
     

6. Push a toothpick through the hole in the middle

7. Spin!

8. Try replacing the toothpick with a pencil (we found the shorter the better). What patterns did your pencil draw?

9. Change the central object and record what happens. What happens if you use a coin instead? And what happens if you make a bigger or smaller disc?


 
     

The Science Behind the Magic

The science behind spinning tops is very complicated and you would need be an expert in physics to understand or explain it all. So here is a cursory introduction to spinning top science…

Starting to spin

When you twist your top to allow it to spin the force you put on it is called ‘torque'. The torque applied on an object gives it ‘angular momentum' making it spin.

To put it more simply, as you will know, when you apply force to an object it accelerates. The science of spinning tops is the rotational equivalent of this.

Spinning

As the spinning top spins it is rotating around an invisible vertical axis. There is a scientific principle called ‘conservation of angular momentum' and this principle explains that it would be possible for a spinning top to spin forever if there was no friction or gravity acting on it.

Stopping

When the top stops spinning it is because of friction and gravity. The friction comes from the contact the top has with the surface below it. Once it has hit this surface the friction causes the top to slow and to wobble. As it loses the balance it had gravity pulls it over which makes it eventually stop moving.

 

Top Tip: For another unique spinning top you can hot glue a marble to the centre of an old CD. 

Don't Make, Just spin: Try spinning a boiled egg, egg toy or an acorn!


Watch a spinning top in space here

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