Solids and Structures - Vector question

[J.Halliwell]

Homework Statement

The rope BC exerts an 800 N force F on the bar
AB at B. Determine the vector components of F
parallel to the bar.

Homework Equations

I already know how to complete dot product (e.g. a.b), cross product (e.g. axb) and understand the basic principles of these ideas but don't know how to use these within the question asked to get the answer.

The Attempt at a Solution

I have already been given the solution to the question but all my workings that I have done so far have not produced the correct answer. The answer is Ans: -396i –476j – 79k N

 

[nvn]

J.Halliwell: The given answer is correct. You must list relevant equations yourself, and show your attempt(s); and then someone might check your math.