mr. bob is very good friends with Mr. jeff and likes to rearrange Mr. jeff's classroom desks around. The coefficient of kinetic friction between the plastic legs of the desks and the tile is 0.3. The desks have a mass of 17 kg each. Mr. bob applies of a force of 60 N to the desk. What is the NET FORCE on the desk? (Net Force = Fa - Ff in this case)