Question

What is cosα for force vector F = Ax + By +Cz (Given α, β and γ are the angles made by the vector with x, y and z axis respectively)?

(a) B/F

(b) C/F

(c) A/F

(d) 1

The question was posed to me in an interview for internship.

Enquiry is from Cartesian Vectors topic in portion Force Vectors of Engineering Mechanics

Answer 1

The correct answer is (c) A/F

To explain I would say: The cosine component of the vector is defined as the ratio of the x-axis component to the magnitude of the vector, i.e. F in this case. Likewise, the sine component is the ratio of the y-axis component to the magnitude of the vector.