Answer
$1125 N m$
Work Step by Step
Hooke's Law states that $F=k x$
or, $k=\dfrac{F}{x}=\dfrac{90}{01}=90$
Use formula: $\int x^n=\dfrac{x^{n+1}}{n+1}+C$ and the work done can be found for the limits for $x$ , that is, $0$ to $5$ as follows:
This implies that $W=\int_0^{5} 90 x dx$
$\implies W= 90[ \dfrac{x^2}{2}]_0^{5}=45[ 25-0] =1125 N m$
