1. The problem statement, all variables and given/known data A block with mass m1 = 9.4 kg is on an incline with an angle θ = 31.0° with respect to the horizontal. Now a new block is attached to the first block. The new block is made of a different material and has a coefficient of static friction μ = 0.9. What minimum mass is needed to keep the system from accelerating? 2. Relevant equations Ft,1 = Ft,2 Fg,1 = m1*g Fg,2 = m2*g Fn,1= Fg,1*cos 31 Fn,2 = Fg,2*cos 31 Ff,s,2 = Fn*.9 3. The attempt at a solution Ft,1 = Ft,2 Fg,1 = m1*g = 92.12N Fg,2 = m2*g = m2*9.8 Fn,1= Fg,1*cos 31 Fn,2 = Fg,2*cos 31 Ff,s,2 = Fn*.9 I'm not really sure what to do after this. I have some free-body diagrams set up, but since I can't post them here, I can't show them. I had a value for the coefficient of static friction, but that was for a system with a spring (.292), so I don't think that'll work here. I also have one for kinetic friction (.212), but that might not apply here. After that, I'm stuck.