OA = 2m
OB = 4m
F1 = 5N
F2 = 3N
As we know,
Moment of force = F × r
Substituting the values of F and r
(i) Moment of force F1 about O = 5 × 2 = 10 N m
(ii) Moment of force F2 about O = 3 × 4 = 12 N m
(iii) Total moment of two forces about midpoint is = 12 N m – 10 N m = 2 N m
Therefore, total moment of two forces about O is 2Nm (clockwise)