The September 2015 paper “Bouncing Back from ‘Deflategate’” is a very interesting article from a physics viewpoint. However, we doubt that the National Football League (NFL) officials will bounce footballs and measure the coefficient of restitution to verify that the footballs remain properly inflated. The release of a few pounds per square inch (psi) from a football seems trivial until one reads about the millions of dollars in suspensions, fines, and legal fees that were accrued. What is a possible solution that the NFL might actually use? Weigh the ball! When a small amount of air is deliberately released, causing a change in pressure, the change in mass can be calculated and measured. Note that the change in mass can be measured without making another pressure measurement. This is important because the reinsertion of the needle of the gauge to make another measurement causes a small inadvertent loss of pressure and mass from the ball.

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G.
DiLisi
and
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4.
For example, Ohaus Scout Pro Portable Balance, 600 g/0.01 g.
5.
See similar volume estimate assuming a paraboloid of revolution rather than a prolate spheroid in this issue,
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 et al, “
Deflategate”: Time, temperature, and moisture effects on football pressure
,”
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