A long plank is balanced on a pivot at its centre of gravity. Two objects, X and Y, are then positioned on the plank. X has a weight of $140\text{ N}$ and is $1.2\text{ m}$ to the left of the pivot. Y has a weight of $220\text{ N}$ and is $0.55\text{ m}$ to the right of the pivot. A third object with weight $110\text{ N}$ is placed on the plank so that the plank remains in equilibrium. On which section of the plank is the object placed?
Physics 5054 · O Level · Turning effect of forces