A meter rule is supported on a knife edge placed at the 40cm mark. the rule balances horizontally when a mass which has a weight of 0.45N is suspended at the 15cm mark.
i) draw the diagram to show the rule, the support and the weight.
ii) describe the forces acting in the system you have drawn.
iii) calculate the moment about the knife edge of the force due to mass of the rule when the rule balances on the knife.
iv) if the rule is 0.90N, calculate the position of its center of gravity.