- #1

- 6

- 0

Hey PhysicsForums. Long time reader looking for some assistance

[PLAIN]http://img205.imageshack.us/img205/3923/physicsg.jpg [Broken]

I'm pretty sure the idea is to find the unit position vector to point A, and the force vector F.

I found the unit position vector to be u = (-4/6)i +(4/6)j + (2/6)k, and the force to be F = (560cos60sin30)i + (560cos60cos30)j + (560sin60)k

Dotting them together gives me 230 lb, but Mastering Engineering doesn't agree with me. Can anyone point out where I went awry?

Thanks for reading!

## Homework Statement

[PLAIN]http://img205.imageshack.us/img205/3923/physicsg.jpg [Broken]

**2. The attempt at a solution**I'm pretty sure the idea is to find the unit position vector to point A, and the force vector F.

I found the unit position vector to be u = (-4/6)i +(4/6)j + (2/6)k, and the force to be F = (560cos60sin30)i + (560cos60cos30)j + (560sin60)k

Dotting them together gives me 230 lb, but Mastering Engineering doesn't agree with me. Can anyone point out where I went awry?

Thanks for reading!

Last edited by a moderator: