Psi, Playing Surface, and a Basketball's Bounce

Research Questions:

• Is air pressure important?
• Do playing surfaces affect performance? If so, which air pressure performed best on which surface?
• Besides wood and cement, can you think of a better playing surface?
• Does dropping the ball from a higher starting point cause the ball to bounce more than when it’s dropped from a lower point? Why?

Materials:

• An adult for assistance
• 3 basketballs: 1 basketball at 8 psi, 1 basketball at 9 psi and 1 basketball at 6 psi (psi = pounds per square inch)
• 1 Air pump
• 1 Pressure gauge
• 1 “Yardstick” style tape measure
• 2 Different surfaces: 1 wood surfac,; 1 concrete surface
• Marker (mark each basketball with the correct psi)

Experimental Procedure:

1. With the help of an adult, fill each basketball with the suggested pounds per inch (psi) and use the marker to label each basketball.
2. On the wooden surface, ask one volunteer to hold the tape measure and ask two other volunteers to stand on each side of tape measure.
3. Ask a fourth volunteer to stand in front of the tape measure and drop one basketball in front of the tape measure.
4. Ask the volunteers on each side of the tape measure to record the approximate height it bounced. (Example: Basketball #1 = 6 psi and bounced 10 inches high).
5. Have the same volunteer who dropped the first basketball continue with the other two basketballs.
6. Ask a significantly taller or shorter fifth volunteer to perform the same steps as the fourth volunteer and record the results.
7. Repeat steps 2-6 on the cement surface.
8. Analyze your data and answer the research questions.

Terms/Concepts: air pressure, surfaces, performance, psi

References:

"Does it matter how much pressure is in a basketball?," Science Projects for Beginners, by Nancy O’Leary and Susan Shelly http://www.infoplease.com/cig/science-fair-projects/matter-much-air-basketball.html

Sports Science Fair Projects: A Great Science Experiment http://www.easy-science-fair-projects.net/sports-science-fair-projects.html

Sports Engineering Science Fair Project, by Julian Trubin (2003-2011) http://www.juliantrubin.com/fairprojects/engineering/sportsengineering.html