Answer
$8.6 \ MPa$
Work Step by Step
We know that pressure is equal to force over area. Thus, we find:
$ P = \frac{5.6\times10^3N}{\pi \times (.025^2)}= 2.85\ MPa$
We multiply this by 1.5 to account for the extra pressure it can withstand, and then we divide by 1/2 to find:
$ \frac{2.85 \times 1.5}{.5}=8.6 \ MPa$