Will the balloon racer go farther with or without weight?

Hypothesis

If I add various weight to the middle of the balloon racer, then it will move farther than a car without weight.

Problem

Will the balloon racer go farther with or without weight?

The following is the procedure used to make my car:

Materials for Balloon Car Racer:

• Piece of cardboard
• 1 rubber band
• 1 balloon
• 4 wheels
• 2 non-flexible straws
• 1 flexible straw
• Tape

Step 1:  Cut a piece of cardboard measuring 8” x 6”.  Decide which side is going to be the top and which one is the bottom.

Step 2:  On the bottom side of the cardboard, place two straws (without a flexible center) about 1” from the front and back of the cardboard.

Step 3:  Insert a dowel rod, smaller than the straw, inside the straw.  This will be the axle rod of the car.

Step 4:  Place four wheels (I used wooden, premade wheels), on the ends of the dowel rod.

Step 5:  Tape ends of dowel rod so wheel won’t fall off.

Step 6:  Take a straw with a flexible middle, bend it in half where the flexible part is, and cut two ends, the same length, making a piece about 5” inches long.

Step 7:  Cover the flexible piece of straw with a balloon.  You want to have about 1 ½” of the straw inside the balloon neck.

Step 8:  Secure the balloon on the straw with a rubber band.

Step 9:  Blow into the balloon to make sure there is no air leaking out.

Step 10:  Position straw with the attached balloon, to the bottom of the racer.  The straw needs to be sticking out about 1½’ from the edge of the cardboard.

Step 11:  Flip the car over and you are ready for a test run.

Procedure/Experiment

Materials for experiment:

• 1 set of lungs
• 1 balloon car racer
• 1 tape measure
• 3 pennies, nickels, dimes and quarters

Step 1:  Decide to use kitchen floor to run experiment.

Step 2:  Draw three circles on the top and in the middle of the balloon racer.

Step 3:  Tape three pennies on top of each circle.

Step 4:  Blow three puffs of air into the balloon.

Step 5:  Pinch the balloon closed with fingers.

Step 6:  Place racer on starting line on the kitchen floor.

Step 7:  Let go of the balloon.

Step 8:  Measure distance from starting line to finish line with tape measure.

Step 9:  Remove pennies from the racer and replace with the next set of coins.

Step 10:  Repeat experiment with three nickels.

Step 11:  Repeat experiment with three dimes.

Step 12:  Repeat experiment with three quarters.

Results

The car, when no weight was added to it, went further than any of the times when weight was added to the car.  The car, when the three dimes were added, went the second farthest.  The car, when the three nickels were placed on it, went third farthest, followed by the three quarters then the three pennies.

No weight added to the car:	Three dimes:
1.     70 ¾” 2.     92” 3.     108 ¾”	1.     62” 2.     62 ¼” 3.     67 ¾”
Three pennies:	Three quarters:
1.     47” 2.     40 ½” 3.     40 ½’	1.     51 ½” 2.     44” 3.     47”
Three nickels:
1.     48 ½” 2.     54” 3.     51”