1. The problem statement, all variables and given/known data You use 30N (**Not 25 N, that was a typo) to slide a wooden box that is 12 kg across a floor at constant velocity. What is the coefficient of kinetic fricition? 2. Relevant equations Ff=coeff of kinetic friction (mu k) m*g ?? not sure. 3. The attempt at a solution coeff of kinetic friction=12 kg/30N=.4. That answer is obviously incorrect, but I don't know what to do. Thanks in advance.