The hypothesis was generally true. As the concentration of the salt in the water went down, the car went slower.

I cannot however explain two things.

First, why the car started going faster around 10000 – 13000 ml, as compared to 9000 ml.

Second, I cannot explain why the car suddenly went slower between 5000 ml and 6000 ml. These would be good research projects for the future.

Tip for kids: For Hot Wheels™ Formula Fuelers, if you choose liquids that taste salty the car will probably go fast.

Bibliography

Benchmark Books. The Elements: Sodium. New York: Marshall Cavendish Books, 2002.

Drago, Christina and Antonella Meiani, (Editors). The Big Book of Experiments: An Encyclopedia of Science. Trans. Maureen Spurgeon. England: Brown Watson, 2000

Voth, Danna. Kidsource: Science Fair Handbook. Los Angeles: Lowell House Juvenile, 1998.

Conversations with my father about electrical circuits.

Also, I would like to thank Ms. Robinson, my teacher, for her help!