Breaking News! Plastic Drinking Straw Pierces Raw Potato

In Science today we wondered, “Is it possible to push a plastic drinking straw straight through a raw potato?”

Here is a collaborative piece of writing from the children of Room 6 telling you how we did the experiment and what we found.

Our hypothesis/Prediction:

It is NOT possible to push a plastic drinking straw through a raw potato.

Materials that you'll need for the experiment:

Stiff plastic drinking straws (not the ones with the bendy bit at the end) and a raw potato

Method/Instructions:

Hold a plastic drinking straw by its sides (without covering the hole at the top) and try quickly piercing the potato.

Repeat the experiment with a new straw but this time place your thumb over the top, covering the hole.

Observation:

When we didn’t put our finger over the hole, the straw bent and did not go through the raw potato, but when we covered the hole at the end of the straw and pushed it quickly, it went straight through the raw potato.

Discussion:

Placing our thumb over the hole at the top of the straw improved our ability to pierce the potato skin and push the straw into the potato. We discussed why we were more successful on the second attempt.

What's happening?:

Covering the top of the straw with our thumb trapped the air inside, forcing it to COMPRESS as we quickly pushed the straw through the potato skin. This made the straw strong enough to pierce the potato, unlike the first attempt where the air is pushed out of the straw.

Later research:

Without our thumb covering the hole at the end of the straw, the air was pushed out of the straw and the straw crumpled as it hit the hard potato. Placing our thumb over the end of the straw trapped the air inside. The air MOLECULES compressed and gave the straw strength. The trapped, compressed air made the straw strong enough to cut through the skin of the potato.

Who knew air could have such strength?

At the end of our experiment, we created a Science Rap using 'Lyric Lab'. Here is Caesar entertaining us...