(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Determine the tension in cables BC and BD, and reactions at the ball-and-

socket joint at A for the mast shown in the figure.

Answers are given by the teacher for checking purposes: TC=707 N; TD=1500 N, Ax=0 N,

AY=0 N, AZ=1500 N

2. Relevant equations

ƩM_{x}=0

ƩM_{y}=0

ƩM_{z}=0

ƩF_{x}=0

ƩF_{y}=0

ƩF_{z}=0

3. The attempt at a solution

Taking clockwise to be the positive moment direction about the x-axis. In other words, if you are standing at the positive side of the x-axis and look down towards the negative side, the moment will be spinning clockwise.

ƩM_{x}=0= -1kN(6m) + T_{BD}cos(tan^{-1}(3/6))cos(45)[kN]*(6m)

....this attempt at a solution is way wrong.

The way I thought about it was, take the cos(tan^{-1}(3/6)) to get your T_{BD}in the yz-plane. Next, I took the cos(45) to get it going strictly in the y direction, and then multiplied by the perpendicular distance from the x-axis, 6 m. The problem I'm having is knowing what to do with the given force of 1 kN. There is no specified direction or any information stating where this force is going to. I know how to use the moment and force equations if I can get these things broken up into components correctly.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Simple Statics Problem

**Physics Forums | Science Articles, Homework Help, Discussion**