1. The problem statement, all variables and given/known data At a construction site, a 62.0 kg bucket of concrete hangs from a light (but strong) cable that passes over a light friction-free pulley and is connected to an 80.0 kgbox on a horizontal roof (see the figure (Figure 1) ). The cable pulls horizontally on the box, and a 50.0 kg bag of gravel rests on top of the box. The coefficients of friction between the box and roof are shown. The system is not moving. μs = 0.700, μk = 0.400 https://session.masteringphysics.com/problemAsset/2039115/1/YF-07-29.jpg The question I am trying to answer is part B: Find the friction force on the box. 2. Relevant equations F = μN 3. The attempt at a solution m_box = 80.0kg m_sand = 62.0kg F = μN F = μmg F = μ(mbox + msand)g F = 0.700(80.0kg + 62.0kg)9.81 F = 893 N So I have already got the answer wrong on mastering physics after 5 attempts and it revealed that the answer is 608N. I can't for the life of me figure out what I did wrong or how to actually get 608N.