1. The problem statement, all variables and given/known data A cat walks along a uniform plank that is 4.00m long and has a mass of 7.00kg. The plank is supported buy two sawhorses, one .440m from the left end of the board and the other 1.50m from its right end. When the cat reaches the right ened, the plank just begins to tip. What is the mass of the cat? 2. Relevant equations ƩFx = 0 ƩFy = 0 Ʃτ = 0 τ=I∂=Fr 3. The attempt at a solution This is a solved example from my book, but I don't understand how they do it. They're saying to calculate the torque about the right sawhorse, so they do Mg(.500m) - mg(1.50)m = 0 This is probably an obvious one but, I have no idea where the .500m came from. Can someone explain this to me?