A $40\mathrm{.}4$kg box initially at rest is pushed $6\mathrm{.}1$m along a rough, horizontal floor with a constant applied horizontal force of $346\mathrm{.}2$N$.$

The coefficient of friction between box and floor is $0\mathrm{.}074.$ Find the work done by the normal force.

Input your answer to the nearest Joule. Use g$=9\mathrm{.}8$m$/$s$2$