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Science Rocks!

Can Car


your results

Sent in by:
Sarah of St. Louis, MO

Vrrroom! Make a racing car out of an old coffee can.

Materials Needed

  • coffee can and two coffee can lids
  • can opener
  • rubber bands
  • masking tape
  • bead
  • pencil
  • paper clip
  • tape
  • unsharpened pencil
  • liquid soap



  1. Cut off the bottom of an empty coffee can with a can opener. Have an adult help you to do this because the edge can be sharp.
  2. Use scissors to punch a hole in the center of both coffee can lids. Make sure the hole is large enough for a rubber band to pass through easily.
  3. Push one end of a rubber band through one of the holes, and hook it around a paper clip on the outside of the lid. Tape the paper clip in place over the hole so that the rubber band cannot pull through the hole. Place the lid with the rubber band on the can.
  4. Reach into the can and grab the rubber band, but be careful of the edges of the can.
  5. Slide the free end of the rubber band through the hole in the other lid, from the inside. Slip the end of the rubber band through a bead so that the bead is on the outside of the lid.
  6. Slide a pencil through the part of the rubber band that is on the far side of the bead from the can, so that the pencil stops the rubber band from pulling back through the bead and the lid.
  7. Adjust the position of the pencil so that the end of it extends past the edge of the can. If it is too short, get a longer pencil.
  8. Put the liquid soap around the edges of the can so that it cuts down the rubbing and slides better.
  9. Wind up the pencil until it comes back to you freely and put the can on the floor. When you let go, off goes the car.

Now it's time for you to experiment. Think of a question you want answered. Like, how can you make it go faster. Will it go faster if you use different sized cans? What about putting some weight on the inside of the coffee can? Make a prediction. Then, change one thing-that's the variable-and test it out. When you're done, send your reports to our special feedback area. Be sure to tell us what you thought was going to happen and what actually did happen. Each week we'll publish a whole bunch.

Some of your Results

Hardik, age 15 of Mason, OH wrote:
My car Failed

Jenny, age 14 of Mason, OH wrote:
It came out okay when I did it. It was pretty easy to make it. It didn't go that fast but it went pretty slow at first, and then it went a little faster.

Taylor, age 14 of San Diego, CA wrote:
Mine worked really good! I kept adding weights onto the rubber band and it made it go faster! I had so much fun making this.

Jonathan of Hazy, VA wrote:
what will be the best sized rubberband

Kelsey, age 15 of Mason, OH wrote:
AMAZING, the experiment ever. You guys explained it really well, I made it in like 2 minutes. Thank you.

Margo of OH wrote:
It didn't work at first, then I figured out you had to wind the pencil a lot to make it go. It was hard to get the rubber band through the bead, but that was the only difficult thing.

Sami, age 14 of OH wrote:
It worked... if you put two rubber bands on the inside then it goess faster.

Karlos, age 15 of Mason, OH wrote:
What I find works better is adding a second rubber band. If you use half of a chopstick instead of a pencil, your results will be better. I had to do this for a school project.

Kevin, age 15 of Mason, OH wrote:
I'm only doing it for a science project.

Leeroy, age 15 of Mason, OH wrote:
It didnt work.

Residents @ Coventry of Sterling, IL wrote:
after 4 or 5 tries with different rubber bands, a longer rod instead of a pencil and then back to the pencil the residents of the Nursing Home and I got it to go across the floor-next time we will get stronger rubber bands and try the toliet paper tube with the cd's- It was alot of fun!

Charlotte, age 11 of Los Angeles, CA wrote:
I tried it a little differently and it didn't really work. it only rolled on a smooth surface and only 30 inches but this was a big big help. thank you.

Chelsey, age 10 of Ellenwood, GA wrote:
i had to push it for it to move. but then I came up with an idea! I said to put a magnet 1 foot away from the car an let's see what will happen. well the car moved twords it

Lindsey, age 11 of Edmond, OK wrote:
it rolled and rolled and rolled and rolled and rolled and rolled until it finnaly hit my dog, Mandy. I showed it to my class and they loved it! some of the school bully's even tried it!

Caitlynn, age 11 of Hanover, MI wrote:
when I did the can car it worked it went verry fast I used just the items they said to use it was awsome I even showed it to my parents and my two sissters haylie and gabby they were amased I love zoom its a great learning site for kids and an awsome fun site too!

Matthew, age 10 of Chicago, IL wrote:
it did work. it rolled like a car.

Tavis, age 14 of Ashburn, GA wrote:
My can worked only on slick surfaces but it was tight.

Ashley, age 12 of Geneva, FL wrote:
mine didn't work! I think it was because I used a dog food can and two plastic drink lids, that were to big for it so I used tape. don't try with the stuff I used!

Sophia, age 9 wrote:
it worked it was cool.

Esmeralda, age 7 of NJ wrote:
I got a can and I got stuff to build a can car and it was awsome.

Ennovy, age 14 of Sacramento, CA wrote:
I used a toilet paper tube and CD's for my car. It went very far and was very fast. I recommend the toilet-paper-tube-and-CDs method for a fast and effective car.

Asiayanna, age 16 of Mexico wrote:
When I first did it it was a little hard, but when I kept going with my partener we got it.

Megan, age 15 of Mason, OH wrote:
instead of a coffee can I used a soda can, and I figured out that to release tension, or to make it go faster, I used 2 beads instead of one, also the reason why it went in a circle is because of the eraser part so use the non-eraser side.

Jamya, age 8 of Gary, IN wrote:
it rolled and rolled. it was amazing stuff

Robert, age 13 of Omaha, NE wrote:
It worked perfutly! I used it for a school project! I recomend this for everyone beause it is so easy!

Maya, age 14 of Boston, MA wrote:
It exploded into 10 small pieces. I made it electric.

Valerie, age 11 of Brooklyn wrote:
this is the coolest experement in the WORLD!!! I recomend this project to anyone who needs one!

Taylor, age 14 of Mason, OH wrote:
it didnt work. I dont know if I did something wrong or not. but it isnt working.

Tiffani of Mason, OH wrote:
my car spinneded in a circle and then it like did a little flippy thing. it was weird. and I didn't like it. but whatever it probably is the best thing that I will do in physical science...

Shaniqua, age 15 of Mason, OH wrote:
alrighty so, I made it. then it did a little spiny thingy when I let go of it. it really made me mad. JEE. but it was the best thing we did in physical science.

Mitchell, age 14 of Mason, OH wrote:
The car works O. K. It doesnt go as fast as I would like it to but atleast it works.

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