Figure shows two forces each of magnitude 10N acting at the points A and B at a separation of 50 cm, in opposite directions. Calculate the resultant moment of the two forces about the point (i) A, (ii) B and (iii) O, situated exactly at the middle of the two forces.

A 55 kg student is climbing a rope ladder hanging from a helicopter. While climbing, the student leans 0.35 m backward from the vertical line of the ladder.

(i) Calculate the torque produced about the top support point of the rope ladder due to the student's weight. [Take g = 10 m s^-2]

(ii) Explain why the ladder starts swinging when the student leans backward and how the student should climb to minimize the swinging.

The diagram shows a uniform bar supported at the middle point O. A weight of 40 gf is placed at a distance 40cm to the left of the point O. How can you balance the bar with a weight of 80 gf?

Figure shows a uniform metre rule placed on a fulcrum at its mid-point O and having a weight 40gf at the 10 cm mark and a weight of 20 gf at the 90 cm mark.

(i) Is the metre rule in equilibrium? If not, how will the rule turn?

(ii) How can the rule be brought in equilibrium by using an additional weight of 40gf?