In this experiment we try to answer the question, do Cheetos make an effective bike helmet?

Many kids do an egg drop experiment in school. We figured dropping an egg would be a good helmet test. If the egg in a Cheeto helmet remained unbroken when dropped, we will assume that a head wouldn't get cracked either. We started our experiment by wrapping an egg completely in Cheetos, then wrapping the Cheetos in plastic wrap.

Then we went outside and set up a ladder. We dropped the first Cheeto helmet from 10 feet up the ladder.

We counted down 5, 4, 3, 2, 1, drop.... splat. The egg broke. We did several other drops at different heights to find the maximum distance we could drop the Cheeto helmet without the egg breaking.

8 feet was the highest distance we could drop a helmet without the egg breaking. Using a little math and Torricelli's equation we figured the velocity of an egg dropped from 8 feet. We counted down 5, 4, 3, 2, 1, drop.... splat. The egg broke. We did several other drops at different heights to find the maximum distance we could drop the Cheeto helmet without the egg breaking.

"vi" in this case is 0. There is no initial velocity.

"a" is acceleration. The only acceleration is gravity, 32 feet / second squared.

"d" is the distance the helmet fell, 8 feet.

Plugging in the numbers "d" is the distance the helmet fell, 8 feet.

v = sqrt( 0 + 2 * 32 feet / sec^2 * 8 feet)

v = sqrt( 512 feet ^2 / sec ^2)

v = 22.63 feet / second

If the end velocity is 22.63 feet / second, how far can it go in an hour?

(60 seconds * 60 minutes) * ( 22.63 feet / second) / (5280 feet/mile) = 15.43 mph

Simplified, you can use this formula to calculate the speed in miles per hour of an object dropped from any hight "d", measured in feet: (SQRT( 64 * d) * 3600) / 5280.

Or, here is a chart.

For those wondering how bike helmets are actually tested, here is a video we found on YouTube that shows some actual helmet tests. They're not quite as fun, but are more practical. Perhaps we might do some accelerometer tests in the future.

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