1. The problem statement, all variables and given/known data A uniform plank, of weight 30N and length 3m, resting on two supports. The supports are 0.5m and 2.0m from the left-hand end of the plank. A weight of 18N is suspended from the left-hand end of the plank. By how much should the weight on the left-hand en be increased so that the reaction Y becomes zero? 2. Relevant equations The reactions that have been calculated from the first part of the assignment are 107N for point X and 196N for point Y . 3. The attempt at a solution Calculations from part a) of the question, which was about finding the reactions at X and Y: X x 1 = Y x 0.5 mg = 30N x 9.8m/s X = mg - Y (mg - Y) x 1 = Y x 0.5 1 x mg - 1 x Y = 0.5 x Y 1 x mg = 1.5 x Y 1 x mg / 1.5 = 1 x 30 x 9.8 / 1.5 = 196N X + Y = X + 196N = mg X = mg - 196 = 30 x 9.8 - 196 = 98N 98 + (18 x 0.5) = 107N X = 107N Y = 196N How do I rearrange the calculations from calculating the reactions into finding how much weight that needs to be added? I am pretty sure I need to consider the length (d) of the plank - I can't simply just add 89N to make the 107N into 196N, right? If there is a general formula/calculation for this, that would be very helpful.