A uniform plank PQ PQ\,PQ of length 6 m is supported by a pivot at its centre. A block of mass 12 kg is placed at end PPP. A second block of mass 15 kg is placed at a distance d d\,d m from the centre such that the plank rests horizontally in equilibrium.
Find the value of ddd.
54 exam-style questions on Edexcel A Level Maths Moments, covering 4.1 Moments, 4.2 Resultant Moments, 4.3 Equilibrium, 4.4 Centres of Mass, and 4.5 Tilting. Each one has a worked solution and a mark scheme showing where the marks go.