Question

Which statement is correct about the vector F in the showing the gravitational nature of the forces?

(a) F= Fcos β + Fcos α + Fcosγ

(b) F= Fsin β + Fcos α + Fcosγ

(c) F= Fcos β + Fsin α + Fcosγ

(d) F= Fcos β + Fcos α + Fsinγ

This question was posed to me in an interview for job.

Question is taken from Potential Energy topic in division Principle of Virtual Work of Engineering Mechanics

Answer 1

Correct answer is (a) F= Fcos β + Fcos α + Fcosγ

To elaborate: As we know the α, β and γ are the angles made by the x, y and z-axis respectively. Thus, is the magnitude of the vector is F, the F= Fcos β + Fcos α + Fcosγ. Which means the force is the resultant of all its axis’ components.