# Homework Help: Simple 3D statics problem

1. Sep 24, 2011

### Ortix

1. The problem statement, all variables and given/known data
If cable AB is subjected to a tension of 700N determine the magnitude of the vertical force F in N.

Pic:
[PLAIN]http://img225.imageshack.us/img225/9823/capturespm.png [Broken]

2. Relevant equations
Sum of forces in x y and z direction

3. The attempt at a solution
I am retaking my statics course after i switched majors (long story) and i kind of forgot how to solve this the RIGHT way.

My approach would be first breaking up all the tensions in the x y and z components and summing all of those. I'll end up with 3 equations and 3 unknowns (F, AC and AD). I just feel like that's too much work...

On top of that my book makes use of i j and k but in those problems angles are given (which does make it easier to calculate the components)

Could someone give me a quick rundown on how to solve this?

Last edited by a moderator: May 5, 2017
2. Sep 24, 2011

### Ignea_unda

Sounds like you're doing it right. You've got the forces broken down, solve for the unknowns. Make sure that you're assuming |AB| to be 700N not any one component of it.

3. Sep 24, 2011

### Ortix

turns out working with unit vectors and i j and k is much easier! Thanks for the reply though!