1. The problem statement, all variables and given/known data By means of a towrope, a college girl pulls a sled loaded with firewood toward her sorority house along a level, icy road. The coefficient of friction between the sled and the road is u_k = 0.12 and the mass of the sled plus its load is 157 kg. The towrope is attached to the front of the sled and makes an angle of 36 degrees with the horizontal. How much work must the girl do with a constant pulling force on the sled to pull it 1.0 km while increasing its velocity from 1.0 m/s to 3.0 m/s? 2. Relevant equations Don't know where to start. 3. The attempt at a solution Friend of mine said: F_SG = (mg)/(sin(theta)*((cos(theta))/u_k)) Using that I got 210 N of force, but with work shouldn't we only be concerned with things in the x-direction?