Find the tension in the horizontal cable that supports the boom

[k31453]

Homework Statement

A crane in a marble quarry is mounted on the rock walls of the quarry and is supporting a 2000 kg slab of marble as shown in the figure. The center of mass of the 900 kg boom is located one-third of the way from the pivot end of its 15-m length, as shown.



Given diagram: http://i38.tinypic.com/oqaltx.jpg

Homework Equations

a)Find the tension in the horizontal cable that supports the boom.

The Attempt at a Solution

net torque will be = 0,

at CM the torque will be 1/3 of length X 830 * 9.8 X cos50 ..

but i can't organize it for tension T

 

[SammyS]

Homework Statement

A crane in a marble quarry is mounted on the rock walls of the quarry and is supporting a 2000 kg slab of marble as shown in the figure. The center of mass of the 900 kg boom is located one-third of the way from the pivot end of its 15-m length, as shown.



Given diagram: http://i38.tinypic.com/oqaltx.jpg

Homework Equations

a)Find the tension in the horizontal cable that supports the boom.

The Attempt at a Solution

net torque will be = 0,

at CM the torque will be 1/3 of length X 830 * 9.8 X cos50 ..

but i can't organize it for tension T

It will be easier to solve this problem by considering the torque about the pivot point of the crane -- at the crane's base.