• Sarah Dann

From Coffee Cups to a Car

Hello you wonderful lot!

Here is what I have been working on today! A little bit of Kinetic Energy!

Super simple... but I'm quite sure this is guaranteed to get a squeal of excitement!

If you have more cups, make more cars and have races!

I love this activity because it requires SO few things and is so easy, PLUS will keep those little ones entertained and develop those fine motor skills as they practice their 'winding'!

Also great for an indoor or outdoor activity!

Although I appreciate that not everyone will have paper cups with lids at home, I thought this would give you the perfect excuse to treat yourself to a couple of tasty drinks at a local coffee shop! (Just remember to wash the cups out :)!)

Everything else I think you will have in your home.

What you will need:

  • 2 Paper or Styrofoam cups with lids

  • Tape

  • Paper Clip

  • 3 Rubber Bands

  • Straw

  • Washer

  • Scissors

  • Small coin to draw around

  • Pony Bead * Note: The bead I intended to use the hole was actually too small to fit my rubber band through, so I went scurrying around my home for an alternative and found that a jam nut (nut) did the trick perfectly. Remember it is always about using what you have available. So have a root around :)

For those who are unsure what a jam nut is.


First, draw around your coin in the center of the base of the cup & cut out circle. So your cups looks like this:

Next, tape the bottoms of your cups together:

Then make a hole in both of the lids. This is about the size you want- just big enough to put a rubber band through:

The next thing to do is tie the three rubber bands together:

Next step: Push one rubber band through the hole in one of the lids, attach a paperclip to the rubber band to stop it from being able to be pulled back through, like this:

Now, I made mistake of making the hole too big on the other lid, I contemplated getting a new lid and starting again so it looked 'perfect' for the blog, but then I thought no. For starters it would be a waste of a plastic lid, and I strive to Reduce, Reuse and Recycle. In addition to this, I thought if I made a mistake of making the hole too big, then maybe someone else will too, and I'm here to be real and honest. So, if you cut a hole too big, all I did was, I simply got some card, cut it to fit in the lid of the cup and attached it with some tape and made another hole for the rubber band đź‘Ť.

Next: Flip the cups over and pull rubber band through the length of the cups and through the hole in the other cups lid.

Once the rubber band is through the hole, thread it through your washer and bead or nut. With the small part of rubber band you have left, insert the straw, so it looks like this:

Now all that is left is to wind the straw like in my video above, place it down on a flat surface and ... let it go!

Remember of course, you can always decorate your cars too!

How does this work?

As you twist the straw, potential energy is created and stored in the rubber bands.

When you stop twisting, the potential energy is turned into mechanical energy.

When the rubber bands start unwinding and the straw is on the ground, it means the only place for this mechanical energy to go is into the cups. Therefore the untwisting force causes rotation in the cups, resulting in your car moving forward.

Hope that makes sense!

I was inspired to do this activity for a mother who is going to be in quarantine at a hotel in Australia for two weeks, and was asking for activity ideas for her son. Hope this helps, and I hope you are all having a wonderful weekend!

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