Fun Friday – Rubber Band Experiments – make a paper rocket and a catapult

My children had a couple of days off for mid term break last week, and I thought it would be a good idea to have a little project ready as a back up if they started to get cabin fever. I loved the idea of the rubber band bracelets described in this blog and decided it would be a great way to entertain all three children. However my attempts to purchase the correct rubber bands lead to five shop visits and a surplus of rubber bands in all kinds of shapes and sizes.

Not to be deterred we decided to put some to good use in the name of science ;0)

Elastic bands are great for exploring elasticity and learning about potential energy! When we pull back on a rubber band we store energy in the band and this is called potential energy, when we let go of the rubber band all this energy is released (as kinetic energy) as the band springs back into shape. Anything attached to the rubber band may be flung forwards or upwards with the force of this energy.

 

EXPERIMENT 1 – MAKE A PAPER ROCKET

The first experiment we show uses the potential energy stored in a rubber band to launch a paper rocket.

For this experiment you will need …

  • a piece of paper
  • an elastic band

EXPERIMENT 2 – MAKE A CATAPULT

The second experiment shows how to make a catapult. This time a lot of the potential energy in stored in lollipop sticks; when we push down on the lollipop stick and then let go the stick springs back up and the energy is released and used to shoot a ball into the air!

For this experiment you will need …

  • some lollipop sticks (we used the larger tongue depressors but regular ones are fine)
  • Elastic bands
  • Glue
  • A plastic bottle cap
  • A small ball or other object for launching (there are a few terrified looking lego men in this house at the moment!)

 

A certain junior scientist really enjoyed this particular “experiment” so I have decided to let him show you how…

Count out you lollipop sticks...
Count out you lollipop sticks…

 

 

We found six to eight sticks work best
We found six to eight sticks work best

 

 

Stack them all together and then wrap a rubber band tightly around one end...
Stack them all together and then wrap a rubber band tightly around one end…

 

 

...and then the other.... so it ends up like this!
…and then the other…. so it ends up like this!

 

 

Next... take two more lollipop sticks
Next… take two more lollipop sticks

 

 

This time wrap an elastic band tightly around just one end
This time wrap an elastic band tightly around just one end

 

 

Open out the sticks at one end...
Open out the sticks at one end…

 

 

...and insert the other stack of sticks, pushing them right down to the elastic end
…and insert the other stack of sticks, pushing them right down to the elastic end

 

 

Now you need to use an elastic band to secure it all in place. Use one band and wrap it repeatedly around the two ends of the thick stack and the one end of the other stack .... leaving the other side open
Now you need to use an elastic band to secure it all in place. Use one band and wrap it repeatedly around the two ends of the thick stack and the one end of the other stack …. leaving the other side open

 

 

That is the tricky bit... so here it is from the other side
That is the tricky bit… so here it is from the other side

 

 

Next take a plastic bottle lid, or something similar
Next take a plastic bottle lid, or something similar

 

 

And glue it to the top of your catapult
And glue it to the top of your catapult

 

 

Once the glue is dry you are all set to launch. You can use a small ball or even crunched up paper or tin foil. See how far you can get the ball... or try making a number of different catapult with different numbers of sticks in the big stack and see which one works best
Once the glue is dry you are all set to launch. You can use a small ball or even crunched up paper or tin foil. See how far you can get the ball… or try making a number of different catapult with different numbers of sticks in the big stack and see which one works best

 

 

And of course you can always decorate it!
And of course you can always decorate it!

 

Enjoy!

 

If you tried this out or have any questions just leave me a comment below…. I always love to hear from you!

nao

Science blogger and writer; Owner of Dr. How's Science Wows; Mother of three junior scientists who have taught me that to be a great scientist you need to look at life through the eyes of a child!

6 thoughts on “Fun Friday – Rubber Band Experiments – make a paper rocket and a catapult

  • Pingback: The science of elasticity, energy and rubber - Dr. How's Science Wows

  • March 8, 2014 at 8:54 am
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    Love your junior scientist, he really shows how much fun experiments like these are for kids 🙂

    • March 8, 2014 at 12:14 pm
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      Thanks, yes he had a ball with this one, we made LOTS of catapults ;0)

  • March 7, 2014 at 6:24 pm
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    I’m sorry the plan didn’t go exactly as intended, but I have to say you got a much more original blogpost out of it!

    (Also, your son’s hair is fabulous!)

    • March 7, 2014 at 8:42 pm
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      We still haven’t made the bracelets yet but will do very soon ;0)

    • March 7, 2014 at 8:51 pm
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      Oh and thanks for the comment on R’s hair… I love it too, I’ll be in bits if/when he decides to cut those curls off!

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