The diagram in Fig.1.34 shows a uniform metre rule weighing 100gf, pivoted at its centre O. Two weights 150 gf and 250 gf hang from the points A and B respectively of the metre rule such that OA= 40cm and OB=20cm . Calculate (i) the total anticlockwise moment about O, (ii) the total clockwise moment about O, (iii) the difference of anticlockwise and clockwise moments, and (iv) the distance from O where a 100gf weight should be placed to balanced the metre rule.

Explanation

(i) 6000 gf cm (ii) 5000 gf cm (iii) 1000 gf cm (iv) 10cm on the right side of O