Question

Two forces each of magnitude 2 N act vertically upward and downward respectively on two ends of a uniform rod of length 1 m, freely pivoted at its centre. Determine the resultant moment of forces about the mid-point of the rod.

Answer 1

Magnitude of each force (F) = 2 M

Length of the rod (l) = 1 m

Distance of each end from the centre (d) \[=\dfrac{1}{2} = 0.5\ \text{m} \]

∵ Both forces produce moments in the same rotational direction (Clockwise).

Resultant moment of forces = (F × d) + (F × d)

∴ Resultant moment = (2 N × 0.5 m) + (2 N × 0.5 m)

= 1 Nm + 1 Nm

= 2 Nm (Clockwise)