Answer
$\Delta P=9.0*10^7N/m^2$ or $9.0*10^2atm$
Work Step by Step
We can solve for the change in pressure using the following formula:
$\frac{\Delta V}{V_0}=-\frac{1}{B}\Delta P$
$\frac{-.001}{1}=-\frac{1}{B_{iron}}\Delta P$
$\Delta P=-B_{iron}\frac{1}{-.001}$
$\Delta P=-90*10^9N/m^2\frac{-.001}{1}$
$\Delta P=9.0*10^7N/m^2$ or $9.0*10^2atm$
