Fun Project Idea: Stabbing a potato with a straw!

February 18th, 2013 : No Comments

Fun Project Idea - Cikgu.tv e-learning for kids

Fun Project Idea Potato - Cikgu.tv e-learning for kids

How to stab a potato with a straw

Do you think it is possible to stab a potato with a drinking straw? Find out with this fun science project that shows how air pressure can be used in amazing ways.

What you’ll need:

  • Plastic drinking straws
  • A raw potato

Instructions:

  • Firsltly, hold a plastic drinking straw by its sides, without covering the hole at the top and try to stab the potato. What happens?
  • Now, repeat the experiment with a new straw but this time place your thumb over the top, covering the hole.

What’s happening?

Placing your thumb over the hole at the top of the straw improves your ability to pierce the potato skin and push the straw deep into the potato. The first time you tried the experiment you may have only pierced the potato a small amount, so why are you more successful on the second attempt?

When you cover the top of the straw with your thumb, you trap the air inside, forcing it to compress as you stab the straw through the potato skin. Unlike the first try where the air is pushed out of the straw, this compressed trapped air makes the straw strong enough to pierce the potato.

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