1. The problem statement, all variables and given/known data An 8.5 kg crate is pulled 5.5 m up a 30degree incline by a rope angled 16degree above the incline. The tension in the rope is 140 N and the crate's coefficient of kinetic friction on the incline is 0.26. What is the increase in thermal energy of the crate and the incline? 2. Relevant equations F = mg W = Fdcos(theta) 3. The attempt at a solution I figured, thermal energy could only come from friction so I calculated the work done by friction. N = mgcos(30) Ff = uN = umgcos(30) W = umgcos(30)d = (0.26)(8.5)(9.8)cos(30)(5.5) = 103J but it's wrong!