Chicken and the Clam
Next time you watch a drag race, notice the wheels. Are they solid metal discs, or do they have holes drilled through the rims? I came up with this somewhat silly, but incredibly powerful quick science demonstration to show my 2nd year university students how one set of rims could really make a difference on the racetrack (with all other things being equal).
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I used coconut milk and beans, they were the same weight and the beans landed first
Yes – that’s the trick. You need to find two objects with the same mass (or weight) in order for this to work. If you don’t have a scale, you can place each can on either end of a ruler and find where the balance point is… it should be in the middle.
This experiment shows you how the rolling resistance changes depending on how the mass is arranged. In the clam, it’s a solid chunk, but with the chicken it’s made up of a sloshy liquid which doesn’t rotate around the center the way the clam chowder does. If you roll an empty can, it’s got a different mass entirely, so there are two effects going on coupled together, which makes it more difficult to observe the difference of inertia.
Yes – the gravitational constant is the same for all objects on Earth:
g = 9.81 m/s2 = 32.2. ft/s2
Do those 2 cans really weigh the same? I do not have a scale. Does it not have anything to do with their weight? A can filled with concrete would roll down slower than an empty can at first but then the can of concrete would catch up and pass the empty one, is that correct? Thanks
So if they were both dropped from an airplane, they would both accelerate at the same rate?
Great experiment. I couldn’t find clam chowder so I used cream of shrimp. It worked great. Chicken also won over chick peas and corn. When we were done we rolled a partially full bottle of juice to see the liquid not rolling but rather the container.
Hmm… that doesn’t sound right. I’ve got them playing on our systems over here. What happens if you try a different computer? I peeked into your account and you should have access.
I can not get 2 of the videos to work in this section. The first one and the last one. The pie plate ball trick is the only one we can get to play in this lesson. Trying to teach this in about 2 hours and they worked a few days ago but now say video can not be found or access is denied. Any ideas how to fix this?
The liquid needs to be very thin – no chunkiness or thick consistency… more like a can of water. My guess is that the tomato soup was too thick. Try again?
I’m trying to use soups we have in our cupboard so we used Cream of Chicken as the solid and Tomato as the liquid. We could hear that the soups were solid and liquid like they are supposed to be, but the exp. did not work as expected – the chicken always won! It started off faster and stayed ahead the whole time…I guess the soups are not as solid and liquid like as I thought. Today we’ll try refried beans and diced tomatoes – they sound very liquid like.
paula nemec
Ah, good thinking! Yes, that is why heavier cars do not win quarter-mile races, but rather mile or longer races. The heavier car will have more momentum the faster it goes, counteracting that inertia (rolling resistance).
My son wonders if the clam chowder would win if the ramp were longer. He hypothesizes that because the clam chowder is heavier it will pick up more speed the further is travels and win the race. Is that true?
It’s cool, we used Amy’s Organic Soups; Tuscan Bean & Rice, and -Fire Roasted- Southwestern Vegetables.
The Tuscan Bean & Rice acts like a Solid, like the Clam Chowder, the -Fire Roasted- Southwestern Vegetables acts like a free flowing liquid.
The Tuscan Bean lost by a few or more seconds, making the Southwestern Vegetables the winner!!!
=)
It’s awesome!
Thanks!!!!
Tori Branand, Age 12
Wow… I tried to pick one that you would easily find. You just need a gloppy one that is solid. Even a can of re-fried beans can work if the cans are about the same. Cream of mushroom is a solid in the can when you open it, right? So that could work, too… let me know what you found!
Believe it or not …. I can NOT find Campbell’s Clam chowder. What would be a good substitute? I was thinking maybe Cream of Mushroom or Tomato?
This is experiment is really cool!!!
Holly Thomson age 11
I love this experiment! It’s so fun to watch the cans race!
times 1,000000000000000000!
sevy keble