A non-uniform plank XY XY\,XY has length 4 m and mass 10 kg. The plank is held in a horizontal position by two vertical light inextensible ropes attached at X X\,X and ZZZ, where XZ=3XZ = 3XZ=3 m.
Given that the tension in the rope at X X\,X is four times the tension in the rope at ZZZ.
Find the tension in the rope at ZZZ.
Find the distance of the centre of mass from XXX.