1. The problem statement, all variables and given/known data There's a mass (16.6 kg) on a surface with kinetic coeficient of friction 0.181. it's being pulled by a constant force of 161 N at 26 degrees above the horizontal. The block is displaced 39.1 meters. Calculate the work done by friction. 2. Relevant equations Friction = (mu)Fn, F=ma W = fd 3. The attempt at a solution I've tried to do this 2 ways now, both ended up wrong: First I thought the force doesn't matter since you know mu and the mass and the displacement. so i thought the work done by friction would equal (16.6)(9.8)(0.181)(39.1) since friction = mu Fn and W = Fd. My second attempt, which i only tried because the first was wrong, factored out the vertical component of the pulling force when finding the normal and friction.