1. The problem statement, all variables and given/known data Two supports, made of the same material and initially of equal length, are 2.0m apart. A stiff board with a length of 4.0m and a mass of 10 kg is placed on the supports, with one support at the left end and the other at the midpoint. A block is placed on the board a distance of 0.50m from the left end. As a result the board is horizontal. The mass of the block is: A. zero B. 2.3kg C. 6.6kg D. 10 kg E. 20 kg 2. Relevant equations ∑F = 0 = N1 + N2 - mg - Mg ∑τ = 0 = -1/2 N1 + 1/2 N2 - 1/2 Mg 3. The attempt at a solution Those equations above are a result of a free body diagram I drew. However, if I begin to solve the equation for m, I end up with an expression in terms of N1 (ie. 2N1 = mg). Is there enough information in the question? By the way, I'm calculating torque from the position where the mass is placed.