Hey Ray: Balloons and tacks

PITTSBURGH (KDKA) - Have you ever stepped on a block that your kid failed to put away?  If so, you know it hurts!

Now, what if I told you that stepping on more blocks at that moment would have hurt much less than one?

When you step down on one block, all or most of your weight is focused on that single spot. 

For simple math purposes, if you weigh 150 pounds, that is 150 pounds of force you are pushing onto that block with your foot.  Of course, that is going to hurt.

If you stepped on ten blocks, though, that weight would be distributed among those ten blocks. 

That means 15 pounds of force is pushing on each block which shouldn't hurt as much.

This is the same idea behind a bed of nails!

We are going to do a similar experiment though to show this in action, and all we need are some thumb tacks and a balloon.

If we were to drop a balloon onto one tack, there would be enough force for the tack to pop the balloon, even though the balloon does not weigh that much.

Now, if we set up a bunch of tacks pointing upward and drop the balloon on it what do you think would happen?

Even pushing down on the balloon a little bit doesn't get the balloon to pop. 

That is why the bed of nails trick works, and why stepping on more blocks is better than just stepping on one.  You can show the science behind it with a simple, fragile balloon.