Have you ever noticed that all round objects don’t move the same way? Some are slower, some just keep going. Today we’re going to learn about what makes canned foods roll different from each other! Ready… set… roll!
Materials:
- A variety of canned food, (try to get a variety that contain liquids, like soup, and others that are solid, like refried beans. Try to keep the cans the same size, at least for the initial experiment)
- Something to make a ramp (some thick cardboard, a wooden board, or a cutting board)
- Some books to elevate the ramp
- Stopwatch on a phone/device
Procedure:
- Set up a ramp with some books under one end so that the top is just under a foot off the ground. Try to set up the ramp on a smooth surface like the kitchen floor rather than a carpet.
- Put another book about 4-5 feet away from the bottom of the ramp. This will be where you stop the stopwatch when/if the can hits it.
- Guess which can you think is going to go the fastest. Why do you think it will be that one?
- Start rolling the cans, as soon as the can gets off the ramp start the timer and then stop it when it reaches the book. Try not to push the cans, but instead let gravity roll them down itself.
- Whichever can makes it in the shortest time has gone the fastest. If some cans can’t quite make the distance, try making the distance shorter for all the cans to travel
Explanation:
To measure the speed of something you need to know how much time it takes for an object to travel a set distance. Since these cans all move the same distance, the one with the shortest time moves the fastest.
You should have noticed a few things: cans with liquid in them, like soups, do not go very fast, whereas containers that have a solid mass to them, like chili or refried beans, tend to go faster. Why is that? Think about the water in a can. It sloshes back and forth, sort of knocking the can off balance. This wobbling motion disrupts the forward motion and tends to slow it down.
The solid-filled can doesn’t have anything to wobble the motion and lets it move at a constant and faster speed.
If you tried an empty can, you might have noticed it didn’t have enough weight to carry it very far!
Going further:
Can you think of other types of foods that will be faster than others? What about the size of the can? Will that make a difference in the speed it goes? Try them out and see!
LOOKING FOR MORE science experiments? Find them here!
About the author:
Steve Davala has been teaching math and science to middle and high schoolers in Oregon since 2000. He writes books, plays music, carves wood and he loves learning new things. Ask him a question at steve.davala@gmail.com.