Pumpkin Smash

Every year around Halloween the Baltimore area physics teachers sponsor a "Pumpkin Smash". The idea is for the kids to build containers which will protect pumpkins when dropped from a height of 100 feet onto asphalt. A crane is donated for the purpose, and there are weight and size limitations. There's always a bunch of wacky entries, and a few real cool ones like a pumpkin fitted with home-made whirligig blades which let it spin gently to the ground like a maple seed. (at least I think those are maple seeds).

But one entry was of particular interest: it consisted of a small pumpkin taped inside a motorcycle helmet. I waited with baited breath as it crashed into the asphalt at a speed of nearly 50 mph. The helmet survived. Unfortunately, the pumpkin exploded.

Lesson learned: Don't fly at 50 mph anywhere near ground.

There were several entries based on the success of a particularly successful model from last year. These consisted of inverted tripods made out of bamboo, with the leaves up top to slow it slightly and maintain direction. When these hit, the bamboo would crumple and the pumpkins would roll away unscathed. Any of you kids see the relationship? That's right! Always parachute down and let the aluminum tubing take the impact.

On another note, I was in a seminar which touched on the manufacture of disk drives. It turns out the "read" mechanism "flies" above the head in the wind generated by the rotation. The guy was talking about pitch, angle of attack, and something not unlike ground effect.

-Brian from Baltimore