Answer
$65975\space N$
Work Step by Step
We can write,
$A=2\pi \Delta x=2\pi (1\times10^{-2}m)(3\times10^{-3}m)=18.85\times10^{-5}m^{2}$
Let's write,
$stress=\frac{F}{A}$
$F=(3.5\times10^{8}Pa)\times18.85\times10^{-5}m^{2}=65975\space N$