Question

A balloon has an internal pressure 1.014 atmospheres and a radius 6.7 centimetres. What is the resultant pressure force on the elastic membrane

Answer 1

Given:

$P=\rm 1.014\: atm=102 700\: Pa$

$R=\rm 6.7\: cm=0.067\: m$

The pressure force on the elastic membrane is given by

$$F=P*A=P*4\pi R^2$$ $$F=\rm 102 700\: Pa*4*3.14*(0.067\: m)^2=5790\: N$$

But, due symmetry, the resultant pressure force on the membrane is equal to zero.

Answer: $F=0\:\rm N$