Motion and Forces: Building Cars and Racing Them

By Patrick Ryan on Jun 15, 2015

These two activities are designed to teach students who are blind or visually impaired about motion and forces.  The first activity focuses on building a balloon car and the second one teaches how to race a car made out of disposable coffee cups.

Balloon Car


  • Foam core or corrugated cardboard
  • Wooden barbeque skewers
  • Regular cardboard
  • Straws
  • Tape
  • Balloons
  • Scissors
  • Wire cutters


  1. Make chassis using corrugated cardboard about 6x3 inch.
  2. Make axles using wooden bbq skewers.  Use the size of your car to determine size (about 4 inch).
  3. Make axel mounts using the straws.  Cut two pieces about 3"
  4. Use tape to fix the mounts to the front and back of your chassis. 
  5. Slide the wooden skewers through the middle of the straws. 
  6. Use scissors to cut four quarter-sized pieces of regular cardboard. If it helps, you can trace a quarter or circle of similar size to give yourself some guidelines.
  7. Push the cardboard circles onto the skewers, one on each end of both skewers. 

straw and balloon attached to cardboardstraws attached to cardboard

  1. Cut the mouth ring (the lip that you blow into) off of the balloon. This will allow for a better seal between the balloon and the exhaust pipe. 
  2. For the exhaust pipe, insert a straw approximately 1" into the balloon. Use tape to securely fasten the straw inside the balloon. The tighter the seal, the better your exhaust pipe is going to work.
  3. Mount the exhaust pipe so that the point where the straw and balloon connect is about 1" from the end of your chassis. Taping it at this point is your best bet.
  4. Secure the straw so that it points straight out from the chassis. 
  5. Inflate the balloon and pinch the straw to keep air inside the balloon. 
  6. Place the racer on the ground and let it go!

scissors cutting balloonstraw attached to balloonballoon attached to cardboard with wheels


Drag Racer

two cups stacked on top of each other with a straw attachedMaterials:

  • Two disposable coffee cups and lids
  • Plastic bead with hole ("pony" bead)
  • Small washer
  • Pen or pencil
  • Duct tape (or other strong tape)
  • Several rubber bands
  • Paper clip 
  • Straw
  • Quarter
  • Scissors
lid of a coffee cup with a small washerlid of a coffee cup with a small paperclip


two coffee cups together to create a car

  1. On the bottom of both cups, trace the edge of a quarter with a pen or pencil. Try to keep the traced circle as centered on the bottom of the cups as possible. 
  2. Cut the traced circles out of the bottom of both cups using a pair of scissors. 
  3. Tape the cups together, bottom to bottom, using a strip of duct tape. 
  4. The holes in the bottom should line up.  Poke a hole in the middle of each disposable lid using the pen, pencil, or scissors.  The hole shouldn't be any wider than 5 mm. 
  5. Link several rubber bands together to make a chain that is close to the combined length of the cups. To link the rubber bands, lay two on top of each other and pull them through each other in opposite directions. 
  6. Run your rubber band chain through the middle of the cups.  Push one end of the rubber band chain through the hole in one disposable lid. Attach a paper clip to hold the rubber band in place and push the lid onto the cup.
  7. Push the opposite end of your rubber band chain through the hole in the other lid. Now, thread the rubber band through the middle of a small washer and bead.
  8. Put the straw through the rubber band, just past the bead. Place the rubber band about 2 cm from one end of the straw. Wind your racer by holding the cups in place and repeatedly spinning the straw around the bead.
  9. Set the racer down and watch it go!
building and racing cars collage