1. The problem statement, all variables and given/known data At a construction site, a small crane is raising two boxes of nails on a plank to the roof. One box has already been opened and is half full, while the other box is new. The boxes, including the nails, weigh 10kg (box 1) and 20kg (box 2), respectively and are both the same size. If the coefficient of kinetic friction is 0.3, how fast will the boxes accelerate along the plank, once they start to slide? This is for box 1: m=10kg Uk = 0.3 Weight = 10kg x 9.8 = 98 N angle = 22 2. Relevant equations Fnet = m/a Fgx = mg(sin22) 3. The attempt at a solution So so far I am trying to find the net force, so I concluded I needed to find Fgx Fgx = mg(sin22) = 37 N F(kinetic force) = -0.3(mg) = -29.4 I am not finished but was wondering if someone could at least hint to me as if I am going in the right direction. This has been confusing me for the past hour.