# A rod attached to a wall by a hinge, the rod is also attacked to a cord and a pulley

1. Nov 28, 2008

### XxseanxX_22@h

1. The problem statement, all variables and given/known data
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?
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Nov 28, 2008

### 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.

3. Nov 29, 2008

### XxseanxX_22@h

Re: a rod attached to a wall by a hinge, the rod is also attacked to a cord and a pul

well i got mgtanθ

4. Nov 30, 2008

### tiny-tim

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.

5. Nov 29, 2010

### SeannyBoi71

Re: a rod attached to a wall by a hinge, the rod is also attacked to a cord and a pul

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

Last edited: Nov 29, 2010
6. Nov 30, 2010

### SeannyBoi71

Re: a rod attached to a wall by a hinge, the rod is also attacked to a cord and a pul

Any help please? Would be greatly appreciated!!