To practice Problem$-$Solving Strategy $7\mathrm{.}3$ Conservation of energy with nonconservative forces.

While a roofer is working on a roof that slants at $=36\mathrm{.}0$ degreesdegrees above the horizontal, he accidentally nudges his mm $=8\mathrm{.}50$ kgkg toolbox, causing it to start sliding downward, starting from rest. A frictional force of magnitude fkfk $=22\mathrm{.}0$ NN acts on the toolbox as it slides. If the box starts dd $=4\mathrm{.}25$ mm from the lower edge of the roof, how fast vv will the toolbox be moving just as it reaches the edge of the roof? Assume that the acceleration due to gravity is gg $=9\mathrm{.}80$ m$/$s$2$m$/$s$2.$