For what values of F and θ will the forces as shown in the diagram below be in equilibrium?

A. 60N and 60°
B. 60N and 30°
C. 20√3 N and 60°
D. 20√3N and 30°

Correct Answer:

Option A – 60N and 60°

Explanation

Resolve vertically, 40cosθ = 20, θ = 60°
Resolve horizontally, f = 40sinθ = 40sin60°
= 40(3/√2)

= 20√3 N