1. The problem statement, all variables and given/known data A 5.0 kg box slides up a 10 m long frictionless incline at an angle of 20 degrees with the horizontal, pushed by a 40 N force parallel to the incline. What is the change in kinetic energy? 2. Relevant equations Ek = 1/2 mv2 Ep = mgh 3. The attempt at a solution I tried to assume that vi was zero. Was that incorrect? 1/2 mvf2 + mgh = 0 2.5vf2 = -(5)(9.8)(10/(sin(20))) vf2= -25.89130... ∴ Ekf = 1/2mvf2 = 64.7 N and ΔEk = 64.7 N The correct answer is supposed to be 232.4 J. Help?