Do you ever wonder how the National Basketball Association (NBA) decides how much air should be in the basketballs used during a game? The NBA measures the pressure inside the ball in units of pounds per square inch, or psi. In this activity, you will experiment with the amount of air in a basketball, but you will use the units scientists use to measure pressure called kilopascals, or kPa. We will vary the amount of pressure in the ball, then use the Motion Detector to measure how high the ball bounces.


  • Graph vertical simple harmonic motion.
  • Find how long it takes to make one complete cycle, or period.
  • Find out how the period is affected by pulling the spring further down.