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Experiment: Stick a Straw Through a Potato

Think you can get a plastic drinking straw to easily go through a hard, raw potato? While it might sound impossible, with a little scientific magic, it can easily be done!

 

maTerials:

  • plastic drinking straw
  • raw potato

 

wow-To:

Step 1: Prepare your straw. If you have a bendy straw, you’ll want to cut off the top portion of the straw that bends.

Step 2: Make some observations about the potato and the straw. Is the straw hard? Does it bend easily? What about the potato, is it hard or soft? Do you think the straw is strong enough to stab the potato? Write down your hypothesis (prediction) and then follow the remaining steps.

Step 3: Try to stab the potato with the straw.

Step 4: Try again, but this time place your thumb over the far end of the straw. Keep your thumb there as you stab the potato with the straw again.

 

What in the WOW happened?

With no more effort than on your first try, this time your straw should easily sink into the potato. It’s all about air pressure! By placing your finger over the opening of the straw you’re trapping the air inside the straw. This makes the air molecules compress and gives the straw super strength and prevents the straw from breaking or bending.