Answer
$V=35.7m^3$
Work Step by Step
We know that,
$V=\frac{m}{\rho}$......eq(1)
We also know that;
$Q=cm\Delta T$
This can be rearranged as:
$m=\frac{Q}{c\Delta T}$
Thus equation(1) becomes:
$V=\frac{Q}{c\rho \Delta T}$
We plug in the known values to obtain:
$V=\frac{1\times 10^6(5)}{1\times 10^3\times 1(50-22)}=35.7m^3$