Skip to main content

Balloon Car

Activity Supplies

  • 3 regular-sized drinking straws
  • Styrofoam or foam tray or piece of cardboard 
  • 1 piece of cardstock or cardboard
  • 1 wheel template (disposable cup bottom)
  • 1 piece of string or yarn
  • Markers
  • Masking tape
  • Scissors
  • Stickers (optional)

Specialty Supplies

  • Balloon
  • 2 bamboo skewers or balsa wood sticks
  • 6 pennies or washers
  • Tape measure (1 needed)

Activity Steps

  1. Use the wheel template (cup bottom) to trace and cut out four wheels from the cardstock.
  2. Using the tip of a pencil or bamboo skewer, make a small hole in the center of each wheel and secure with a small piece of tape.
  3. Using scissors, cut two straws such that they are slightly longer than the width of the Styrofoam tray or cardboard chassis.
  4. Turn the Styrofoam tray or cardboard chassis upside down, and tape the straws on each end of the chassis. These will serve as shafts for the wheel axels.
  5. Cut the skewers such that there is ½" (~1 cm) extending beyond each straw end when inserted.
  6. Slide one skewer through each straw. These will serve as the wheel axels.
  7. Put one wheel onto each end of the skewers. Make sure your racecar rolls freely when pushed.
  8. Test your car and demonstrate Newton’s 1st and 3rd laws of Motion:
    1. Carefully cut the elastic rim off the end of your balloon.
    2. Insert the jumbo straw about 1 inch inside the balloon and tape to the straw to secure it in place. Make sure there are no gaps that will allow air to leak. Note: regular straws will also work, but require more caution in taping closed the gaps.
    3. Tape the straw to the top-middle of the racecar body.  The straw opening should stick out a bit from the end of the tray.
    4. Blow into the straw to inflate the balloon and pinch the straw to keep it from deflating.
    5. Place the racecar on a smooth surface and let go of the straw. What happened?
  9. Investigate Newtons 2nd Law of Motion:
    1. Mark a starting line for the placement of your racecar (to be setup by the facilitator).
    2. Blow into the straw to inflate the balloon and pinch to keep it from deflating. Note: Because the balloon provides the force, it is important that it is inflated to the same size for each trial. Using a piece of string, measure the circumference of the balloon at its widest part. Mark the string with a pen or pencil and use to set the balloon size for all trials.
    3. Place the racecar at the starting line and let go of the straw.
    4. Measure the distance the car traveled and record in the data chart.
    5. Place two pennies on the racecar body on top of the Styrofoam tray and repeat steps B-D.
    6. Repeat step E with two additional pennies until you have added a total of six pennies to the tray and recorded data for a total of four trials.

Official Lesson Plan