Question

An object is acted upon by two forces operating 5N and 12 N. calculate the resultant of the force acting on an angle of 120 degree to each other.

Answer 1

if the 5N force acts in the +i direction, then the resultant is
r = 5i + (-6 i + 6√3 j) = -i + 6√3j
|r| = √(1^2 + 108) = √109
at an angle θ where
tanθ = 6√3/-1 = -6√3
θ = 95.5°