1. The problem statement, all variables and given/known data A 40.0kg box initially at rest is pushed 5.00m along a rough, horizontal floor with a constant applied horizontal force of 130N. If the coefficient of friction between box and floor is 0.300, find the work done by the normal force? 2. Relevant equations W=F*d 3. The attempt at a solution The answer is 0N, however i got 1260(which i know does not seem logically correct). So can someone explain to me why does work done by the normal force equal to 0N.