A $76\mathrm{.}0-$kg cross$-$country skier glides over snow. The coefficient of friction between skis and snow is $0\mathrm{.}180.$ Assume all the snow beneath his skis is at $0\backslash$deg C and that all the internal energy generated by friction is added to snow, which sticks to his skis until it melts. How far would he have to ski to melt $2\mathrm{.}80$ kg of snow?