Question

Determine the resultant of four parallel forces acting on the axle of a vehicle as shown in Fig.

Answer 1

Let x and y axes be selected as shown in the Figure 

Rx = ΣF_x = 0 

R_y = ΣF_y = 60 + 20 + 30 + 40 = 150 kN

∴ R = \(\sqrt{0^2+150^2}\) = 150 kN

Taking clockwise moment as +ve, 

ΣM_A = 60 × 0 + 20 × 1 + 30 × 3 + 40 × 4 

= 270 kN-m 

∴ Distance of resultant from A

x = \(\frac{270}{150}\) = 1.8 m as shown in the figure.