1. The problem statement, all variables and given/known data A weight is attached to a wooden body with mass M=4kg lying on a horizontal surface. The coefficient of friction is μ=0.2. What is the mass m of the weight so that the wooden body is moving? Image: 2. Relevant equations Equations of forces 3. The attempt at a solution I tried drawing all the forces that apply on both bodies and then make an inequality where the total sum of the forces applying on the weight is bigger than the ones on the wooden body, but I get an unknown value for the acceleration. Help would be appreciated.