Current Electricity

The current density in a circular wire is given by $J(r)=\left(1 \times 10^5 \mathrm{~A} / \mathrm{m}^3\right) r$, where $r$ is the radial distance and the wire's radius is 2 mm . If the potential applied across the wire is 70 V , then the energy consumed by the wire in 1000 s is