Question

Determine the resulting moment with respect to point O. use the scalar formula for the calculation of moments

de las fórmu 4kN 30 2kN 300 mm 5 KN O 3 kN 400 mm 300 mm

Answer 1

Components of 4kN force

Horizontal component = 4 x Cos (30) = 3.46 kN

Vertical component = 4 x Sin(30) = 2 kN

Moment of a force about a point = Force x Perpendicular distance from line of force to that point

Hence , Moment about O = 3 x 0 + 5 x 0 + 2 x 300 + 3.46 x 300 - 2 x 700 [ $\because$ 3kN & 5kN force passes through O , -ve sign for counterclockwise direction]

                                      = +238 kN.mm

                                      = 238 Nm (Clockwise)