Ryan Minhas
Posts: 1
Joined: Mon Feb 04, 2013 7:44 pm
Occupation: Student

How to measure how much Air Pressure is in a basketball

Postby Ryan Minhas » Mon Feb 04, 2013 7:56 pm

I need to know the max air pressure you can pump in a basketball. I dont know how to reach a gauge yet.

Posts: 350
Joined: Mon Oct 03, 2011 12:26 pm
Occupation: US Air Force Space & Missile Operations

Re: How to measure how much Air Pressure is in a basketball

Postby theborg » Thu Feb 07, 2013 6:42 pm

Ryan Minhas,

Welcome the science buddies and thank you for your question. This is a tricky question. Different manufacturers sell balls of various sizes and materials. These factors will determine How many pounds per square inch (PSI) you can inflate a basketball before it fails. Spalding makes the game balls for the NBA and uses a rubber bladder wrapped in fiber with a leather outer casing (this is the part you see), and has a 29.5 in circumference. Regulation pressure for NBA games is between 7.5 and 8.5 psi. I have never inflated one to failure, but I would expect all these layers to make the ball quite strong. Even so, i've found a couple references that suggest failure may occur somewhere around 80 psi.

I'm not sure what you mean by "I don't know how to reach a gauge yet." Please explain.

If you decide to try this, remember, the effects can be...well...explosive! Make sure you have adult supervision, everyone has proper eye and hearing protection, and you remain well out of the "blast" area or have a cover. You will need a pump with an inline pressure gage either manual or automatic. I suggest filming the gage while the ball inflates then you will be able to analyze the video to determine the psi at the moment the ball explodes.
Hope this helps.

Science Buddies science fair guide:

Science Buddies project ideas:

Return to “Grades 6-8: Getting Ready for the Science Fair”