In the figure below, two blocks are connected over a pulley. The mass of block A is 12 kg, and the coefficient of kinetic friction between A and the incline is 0.22. Angle θ is 30°. Block A slides down the incline at constant speed. What is the mass of block B?

Answer 1

well, the force down the incline+friction= massB*g

12g*sinTheta+mu*12g*cosTheta=massB*g

solve for massB

Answer 2

you actually have to subtract the frictional force not add it