# Waves - a tension question

1. Homework Statement

A 12 kg object hangs in equilibrium from a string with a total length of L=5m and a linear mass density of u= 0.001kg/m. The string is wrapped around two light, frictionless pulleys that are separated by a distance of d=2m. Determine the tension in the string.

Sorry i don't have a picture but - the pulleys are at the top an the rope goes around them with a hanging mass, forming an inverted triangle.

2. Homework Equations

3. The Attempt at a Solution

Normally, i would write equation for the sum of the forces on the x and y axis:

If there was an axis at the bottom of the inverted triangle and the angles were measured from the axis to the strings;

sum of forces on x-axis = T(right) cos theta - T(left) cos theta = 0
sum of forces on y-axis = mg - T(right)sin theta - T(left)sin theta = 0,
But since i don't know the angles, this goes nowhere.

I have also tried using;
v = Square root of (tension/u), but I don't have v,
So i tried to find v using f = v/ wavelength, but i don't have frequency.

I have tried so many things and I can't seem to get a start. Any hints?