c
(image)
$P - P _0=\Delta P =\frac{4 T }{ R }$
$P =\left( P _0+\frac{4 T }{ R }\right)$
Case-$2$
(image)
$P _1-\frac{8 P _0}{27}=\Delta P _1=\frac{4 T }{ R _1}$
$P _1=\frac{4 T }{ R _1}+\frac{8 P _0}{27}$
Constant temperature process
$PV = P _1 V_1$
$\left( P _0+\frac{4 T }{ R }\right) \frac{4}{3} \pi R ^3=\left(\frac{4 T }{ R _1}+\frac{8 P _0}{27}\right) \frac{4}{3} \pi R _1^3 ;\left(\frac{4 T }{ R }\right),\left(\frac{4 T }{ R _1}\right) \rightarrow \text { (Neglected) }$
$R =\frac{2}{3} R _1 \Rightarrow R _1=\frac{3}{2} R$
$\Delta P _1=\frac{4 T }{ R _1}=\frac{4 T }{3 R } \times 2=\frac{2}{3} \times(144)=96 Pa$
