1. The problem statement, all variables and given/known data A metre rule is balanced at the 50 cm mark. If a mass of 5kg is placed 40 cm from the pivot at one end, what mass must be placed 30 cm from the pivot on the other end to balance the rule? 2. Relevant equations M1 * G * D1 = M2 * G * D2 3. The attempt at a solution M1 = 5kg M2 = ? D1 = 40 cm D2 = 30 cm G = 9.8 Therefore 5 * 9.8 * 40 = M2 * 9.8 * 30 = (5 * 9.8 * 40)/9.8 * 30 M2 = 6.66kg Is this correct?