## Tuesday, July 24, 2012

### 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.

## Thursday, July 19, 2012

### Cheeto Conductivity

In this experiment we wanted to find out if Cheetos conduct electricity. For this experiment we used a multimeter, water, and various other liquids.

The test to see if Cheetos, or anything, conducts electricity is easy - turn a multimeter to the connectivity setting (it usually has a symbol that looks like a speaker), and touch the probes of the multimeter to a different side of the thing you are testing. We touched the probes to either side of a Cheeto and quickly determined that they do not conduct electricity.

To make the experiment a little more interesting, we wanted to determine if Cheetos resist or help the flow of electricity through water. This was our experiment.
1. We taped the leads of our multimeter against the sides of a plastic cup.
2. We filled the cup with water to the point were water was touching both leads.
3. We turned the meter to 2000 ohms and measured 251. This was our baseline.
4. We then crushed up several Cheetos.
5. We added the crushed Cheetos to the water and read the new measurement. It was 165.
Because the value of resistance went down, that would indicate that something in the Cheetos helps the electrons through the water from one probe to the other.  Substances that conduct electricity are called electrolytes.

Just for fun, we tested the resistance of various other liquids to see if they are electrolytes. Here are our results.

 Liquid Value Tap Water 251 Tap Water + Cheetos 165 Milk 260 Apple Juice 350 Vinegar 29

Observations: The values of the substances changed with time, more so on the items that are normally kept cold. To get a more accurate measurement, we should probably let the items come to room temperature before testing them.

Here's a small factoid we discovered. The resistance of milk can be used to determine the health of of a cow. Here is a link to a study that was done on buffalo cows. There is a high correlation between a higher than normal resistivity in milk and infected cows.

This was a fun project. The kids liked learning to use the multimeter, and they liked coming up with different liquids to test.

## Tuesday, July 10, 2012

### 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.

$v_f^2 = v_i^2 + 2 a \Delta d \,$
"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.

## Saturday, July 7, 2012

### Cheeto Cannonballs

In this experiment we use Cheetos as cannonballs to figure out which angle will shoot the furthest.

For this experiment we needed a rocket launcher, modified to shoot Cheetos Balls. There are lots of plans on the Internet for compressed air rockets, such as this one from Kip Kay and Make Magazine. We built ours out of 3" pipe in a U shape. Instead of gluing most of the pieces, we opted to use threaded connections that would allow us to change the angle of the launch without repositioning the entire launcher. We added a larger piece of PVC pipe on the end that a Cheetos Balls could fit in - since they wouldn't fit in the 1/2 inch pipe used for launching rockets.

We ran a long measuring tape down the center of our yard. We constructed a large protractor out of cardboard so we could determine the angle. and we filled the launcher each time with 20 pounds of pressure.

We shot three Cheeto Balls from 10, 20, 30, 40, 50, 60, 70, and 80 degrees using 20 pounds of pressure. After shooting a Cheeto, we measured how far it went down this center tape, and the distance it landed away from the center line. Here are the results.

Our purpose in doing the experiment was to see which angle shot the Cheetos the furthest. We didn't measure how far the Cheetos traveled, only how far they went down the center line, and their offset. To determine which Cheeto went the furthest, we needed to use a little math. We had two sides of a right triangle, A and B. Pythagoras came up with the equation to find the length of side C: A squared + B squared = C squared. (This is an interesting YouTube video on the subject, explaining how Pythagoras did not think about his theorem the way we do.)  We applied Pathatoreans theorem to get the actual distances.

 Degree Left -1, Right 1 Center Distance Offset Computed Distance 30 1 630 68 633.66 20 1 604 54 606.41 40 1 588 69 592.03 30 1 584 21 584.38 20 -1 567 -51 569.29

Why didn't each Cheeto land in the same place if shot at the same angle with the same pressure? There was a slight breeze, which might have helped some Cheetos and hindered others. Also, though we tried to always fill the launcher to 20 lbs, there could have been variations.

Why didn't 45 degrees shoot the Cheetos the furthest? The higher the Cheetos went, the more opportunity there was for the breeze to change its course. As Yogi Berra said, "In theory there is no difference between theory and practice. In practice there is."

## Wednesday, July 4, 2012

### Cheeto Plaster Mold

In our last project we created a plastic mold of the perfect Cheeto. In this project we made a plaster mold using the plastic mold we make previously.

For this project we used the following materials:
• File folders (Dad's go to craft supply)
• Molding plaster powder
• Duct tape
• Plastic mold
The first step of this project was to create a circular cylinder in which we could pour the plaster. We cut strips 2 inches wided out of the file folders and wrapped them around a peanut butter jar. We made two just for added strength, and wrapped one around the other.

Then we used duct tape and taped the file folder cylinders to the plastic cheeto mold. We coated the mold with a quick shot of cooking non-stick spray to help separate it from the plaster later on.

We eyeballed enough plaster powder into a paper cup and mixed in enough water until the plaster was the consistency of pancake batter, and poured it into our mold. Then we let the mold sit for about an hour.

When the paster was hard, we removed it from the mold.

Last of all we painted the plaster with acrylic paint.

This was a fun project. If we were to do it again we would make a few modificaitons. First, we wouldn't have used so much plaster. It is much thicker than it needs to be. This just adds extra weight without being very useful. Also, the file folders weren't such a good idea. They got soggy and didn't make a good edge for the plaster. It would have been better to coat the inside of the file folders with duct tape before taping it to the plastic form.

We have also decided that we could make smaller cylinders and make Christmas tree ornaments of the Cheeto mold. Then we could have a Cheeto Christmas to complement our Cheeto Summer of Fun.

## Monday, July 2, 2012

### Cheeto Plastic Mold

Suppose you found the perfect Cheeto and wanted to preserve it. We decided we would experiment with plastic molds and make a vacuum mold of a Cheeto. We got the idea from two of our favorite project sources: Instructables and Kip Kay.

For this experiment we started with:
• A plastic peanut butter jar
• An empty soda bottle
• An empty plastic milk
• Duct tape
• A piece of wood larger than the peanut butter lid
To start our project, we drilled holes in the top of the peanut butter jar lid.

We drilled lots of holes until there were holes over the whole surface.

We cut the top off a coke bottle. This makes a good funnel that will make it easier to connect the vacuum. Then we traced the bottle top onto the side of the peanut butter jar and cut a hole and cut well inside the line.

We put the bottle top through the hole in the peanut butter jar and used duct tape to keep it in place. The bottle should be much wider than the hole so it doesn't come out.

For the last piece of our contraption, we taped a vacuum hose attachment on to the bottle. The tapered end of the bottle makes it easy to connect.

Next we found a piece of wood that was bigger than the peanut butter jar lid. We traced the lid on the wood, and cut the hole out. Then we cut a side off of a plastic gallon milk jug and stapled it over the hole. (We used a staple gun not a paper stapler.)

We put a Cheeto on top of the peanut butter jar, then put the plastic in the oven at 300 degrees four about 2 minutes. The plastic started to melt and burn at that point. We took the plastic out of the oven and placed it on top of the Cheeto and peanut butter jar and turned on the vacuum. The plastic was sucked down around the Cheeto to form a mold.

Here was our final mold preserving the perfect Cheeto.

If we were to to do the project again we wouldn't have made quite so many holes in the top of the lid, and we would have made the holes cleaner. Our mold is bumpy around the Cheeto because of many of the holes touched each other, ripping the plastic and making the surface bumpy. We would also use a heat gun rather than putting the plastic in the oven. We could have used the heat gun to reheat the plastic while it was over the Cheeto to get cleaner and more defined edges.

What can be done with a Cheeto with the mold?
• Make a Play Dough Cheeto
• Fill it with plaster to make a permanent Cheeto
• Fill it with melted chocolate to make a chocolate Cheeto
• Fill it with fondant for a Cheeto cake decoration
• Make a bar of soap the shape of a Cheeto
• Fill it with wax to make a Cheeto candle
Feel free to leave a comment and let us know other ways we might use our Cheeto mold, or other Cheeto experiments we might try.