Weird Science: Stabbing Potatoes

Weird Science: Stabbing Potatoes

HONOLULU (HawaiiNewsNow) - In this week's Weird Science, Dr. V. shows us how to stab potatoes, which is harder than it looks.

Things you need:

· Non-bendy Straw

· Potatoes

The experiment:

Take one of the straws and try poking it into the potato by pushing it slowly in. What happens? Are you able to get the straw into the potato? Does the straw bend? Be sure that your fingers are not on the other side of the potato. Try sticking the straw into the potato quickly; stabbing it in straight and as quickly as possible. What happened this time? You might've been able to even stick the straw all the way through the potato!

How does it work?

The edge of the straw is very thin and can actually be very sharp, like a knife. When you push the straw in slowly, the straw tends to bend. When the straw is straight, it is very strong. Once the straw starts bending it starts to lose its strength. The more it bends, the weaker it becomes and it will eventually fail by buckling and collapsing. So the faster you stab the potato, the less time the straw has to fail.

Another reason this works is the speed of your impact concentrates the force at the tip of the straw. If you slowly poke the straw into the potato, the surface of the potato has time to distort and spread the force out over a wider area. It's like when you're using an axe to cut wood, it's much more effective to swing quickly at the piece of wood, than to push the axe through the wood slowly.