Finding Tension in a Simple Crane System

[XxseanxX_22@h]

Homework Statement

A simple crane consists of a rigid rod that is hinged to a wall at one end and tied to the wall with a horizontal cable at the other end. The rod makes an angle θ to the wall. At the same end to which the cable is attached there is also a frictionless pulley. The rope that is looped over this pulley is attached to a mass m at one end and is held at the other end so that the weight hangs in equilibrium. Given that the gravitational field is g, what is the tension, T in the horizontal support cable?

 

[tiny-tim]

Hi XxseanxX_22@h!

Show us what you've tried, and where you're stuck, and then we'll know how to help.

 

[XxseanxX_22@h]

well i got mgtanθ

 

[tiny-tim]

well i got mgtanθ

hmm … that's not even an equation, that's only the component of the weight of the mass m along the rod.

(btw, what's the mass of the rod itself?)

Hint: in problems like this, start by saying how many forces there are on the rod, and what they are.

 

[SeannyBoi71]

I know this is another old post, but I found that XxseanxX_22@h has posted identical problems in the past that I have right now, I'm thinking he was potentially in the same class I am in now xD (btw, it is just coincidence we have the same name :S)

I am stuck, for net forces I have found that T=sintheta and 2mg=costheta. I'm not sure if those are right, but I'm also having trouble finding net moment about the rod. Any help?

edit: it doesn't actually give you the mass of the rod in the question

 

[SeannyBoi71]

Any help please? Would be greatly appreciated!