The following diagram (Fig. 1.20) shows two parallel and opposite forces F_1 and F_2 each of magnitude 5N, with their lines of action separated by a distance of 2m. A point X is pivoted midway between F_1 and F_2 while a point Y is pivoted on F_2 (a) calculate the total moment of the two forces about the points (i) X, and (ii) Y (b) State the effect produced by the two forces about the points (i) X and (ii) Y

The following diagram (Fig. 1.20) shows two parallel and opposite forc

1.	The following diagram (Fig. 1.20) shows two parallel and opposite forces F_1 and F_2 each of magnitude 5N, with their lines of action separated by a distance of 2m. A point X is pivoted midway between F_1 and F_2 while a point Y is pivoted on F_2 (a) calculate the total moment of the two forces about the points (i) X, and (ii) Y (b) State the effect produced by the two forces about the points (i) X and (ii) Y
Answer» SOLUTION :(a) (i) Perpendicular distance of point X from EITHER of the forces `F_1 or F_2` is `1/2 times 2M=1m` `therefore` Moment of FORCE `F_1` about X `=5N times 1m` =5 Nm (clockwise) and moment of force `F_2` about `X= 5N times 1m` =5 N m (clockwise) Hence total moment of the two forces about X =5+5=10 N m (clockwise) (ii) Perpendicular distance of point Y from the force `F_1` is 2m while it is ZERO from the force `F_2` `therefore` Moment of force `F_1` about Y =`5 N times 2m` 10 Nm (clockwise) and moment of force `F_2` about Y=0 Hence total amount of the two forces about Y =10 Nm (clockwise) (b) (i) The effect of the two forces about the point X is to produce clockwise rotation. (ii) The effect of the two forces about the point Y is to produce clockwise rotation.