Can Cheetos Keep a Car Afloat?

It is impossible to do most anything now without wondering if there is some way to relate it to a Cheeto experiment. Recently we went boating on a beautiful lake. Today we tried to answer the question:

How many bags of Cheetos would it take to keep a Honda Fit afloat?

A Honda Fit has a curb weight of 2423 lbs. What would be your guess? In the group of people we asked there was a low of 500 bags, and a high of 500,000, an average of 53,800, and a median of 10000 bags.

The Experiment

To do this experiment we used a cooler, a large bag of Cheetos Puffs, two hangers, and a measuring cup.

1. We filled the cooler about half full with water.
2. We put the unopened bag of Cheetos into the cooler.
3. We used the hangers to completely push the bag of Cheetos underwater.

4. We marked the water level.
5. We removed the Cheetos from the water.
6. We measured how much water it took to fill the cooler to the mark.

Results

Archimedes' principle states that the upward buoyant force will be equal to the weight of the displaced water. Google helped us find the weight of a gallon of water, 8.345 lbs. It took 26 cups of water (1.625 gallons) to fill the cooler to the bandaid. 8.345 * 1.625 = 13.561 lbs. Each bag of Cheetos weighs 9.75 ounces or 0.609 lbs. To find out how much buoyancy lift each bag of Cheetos provides we will take the total displacement weight of the bag of Cheetos minus the weight of the bag.

13.561 - .609 = 12.952 lbs total buoyancy.

To find the total number of bags required we will take the total weight of the car, 2423 lbs, and divide the total buoyancy of one bag of Cheetos, 12.952 lbs.

2423 / 12.952 = 187.075 bags of Cheetos. Since we don't have fractional bags of Cheetos we will round up to 188 bags. 188 bags of Cheetos will float a Honda fit.

How many bags would it take to keep your car afloat?  Google "curb weight" and the name of your car. Divide the curb weight by 12.952 to figure it out.

This is a simple experiment and was entertaining for everyone involved. It was easy have lots of parts for everyone to perform, and it helped to get every one's predictions first.
Now, do you think it will be possible to get Frito Lay to donate 188 bags of Cheetos so we can test our theory? Maybe Mythbusters would take on the experiment to build an actual raft with Cheetos.

Cheeto Bike Helmets

Have you ever wondered how bicycle helmets are tested? I've wondered if it was someones job to wear a helmet while a weight was dropped from progressively higher distances onto their head. After each impact they would be asked, "Did that hurt?"

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. 


"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
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.  

Our experiment shows that a Cheeto helmet can withstand an impact of 15 miles per hour.  So would Cheetos make a suitable bike helmet? You would probably be alright if your head hit the ground slower than 15 miles per hour. Not only could the helmet protect your head, but imagine the fashion statement you could make in the neighborhood with a helmet made out of Cheetos. And it would be a convenient snack!  This was a fun Cheeto experiment that didn't take a lot of time.

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.