Answer
$l=83.76m$
Work Step by Step
We know that
$V=\frac{m}{\rho}$
We plug in the known values to obtain:
$V=\frac{1.10}{2700}=4.074\times 10^{-4}m^3$
We also know that
$V=l\times a \times b$ Where $l$,$a$ and $b$ are length, width and thickness
The above equation can be rearranged as
$l=\frac{V}{a\times b}$
We plug in the known values to obtain:
$l=\frac{4.074\times 10^{-4}}{304\times 10^{-3}\times 0.016\times 10^{-3}}=83.76m$