Question

An air-filled rubber ball has a diameter of 6 in. If the air pressure within the ball is increased until the diameter becomes 7 in., determine the average normal strain in the rubber.

Answer 1

we are given

An air-filled rubber ball

$d_0=6in$

$d=7in$

we can use formula of the average normal strain in the rubber

$\delta =\frac{\pi d - \pi d_0}{\pi d_0}$

now, we can plug values

and we get

$\delta =\frac{\pi*7 - \pi*6}{\pi* 6}$

$\delta =0.16667in/in$...........Answer