Strong Straws and a Potato

This super simple STEM challenge requires only a straw, a potato and a willing volunteer.

You'll need

Two paper straws

A large potato ( raw )

Instructions

Pick up one of the straws and try to push it into the potato hard. The straw will most likely bend.

a bent paper straw resting on top of a potato

Take the second straw, and this time cover one end with your thumb. Try and stab the potato again. You should find the straw makes a hole in the potato!

A paper straw which has been pushing into a potato as part of a science challenge

Why does it work?

Paper straws are not particularly strong. If you bang them on a table, they will usually bend, which is what happens if one is used to pierce a potato.

However, when the end is covered, air is trapped inside the straw. When the straw is pushed into the potato, the air is compressed, which increases the rigidity of the straw, making it strong enough to pierce the potato!

If you enjoyed this post, you might like my easy STEM challenges using newspaper too!