Two forces each of magnitude 2N act vertically upwards and downwards respectively at the two ends of a uniform rod of length 1m which is pivoted at its centre. Draw a diagram of the arrangement and determine the resultant moment of forces about the mid point of the rod.

Two forces each of magnitude 2N act vertically upwards and downwards r

1.	Two forces each of magnitude 2N act vertically upwards and downwards respectively at the two ends of a uniform rod of length 1m which is pivoted at its centre. Draw a diagram of the arrangement and determine the resultant moment of forces about the mid point of the rod.
Answer» Solution :The arrangement is shown in fig.1.21 GIVEN below . AB is the ROD which is pivoted at its centre O. Given `AB=1m therefore OA=OB=0.5m` Moment of force F (=2N) at A about the POINT O `=F TIMES OA =2 times 0.5 =1.0 Nm` (clockwise) Moment of force F (=2N) at B about the point O `=F times OB=2 times 0.5=1.0 Nm` (clockwise) `therefore` TOTAL moment of forces about the mid point O `=1.0+1.0=2.0 N m` (clockwise)