# A static equilibrium problem is solved with torques

I was doing some static equilibrium problems and I came across this problem which should be easy to solve, but is posing quite a challenge. I want to point out that this is **not** homework, just plain old studying. By the way, I don't know how to format mathematical equations and I think writing them out here without any formatting is a mess, so I took phtographs of the relevant bits. If any brave soul feels up to the task, I'd greatly appreciate it :)

## Problem-Solving Strategy: Static Equilibrium

Photo provided by Flickr

### 10-11 A General Method for Solving Static Equilibrium Problems

This example shows that when solving static equilibrium problems, we are free to choose the pivot location. For different choices of the pivot point we have different sets of equilibrium conditions to solve. However, all choices lead to the same solution to the problem.

### A General Method for Solving a Static Equilibrium Problem.

All examples in this chapter are planar problems. Accordingly, we use equilibrium conditions in the component form of to . We introduced a problem-solving strategy in to illustrate the physical meaning of the equilibrium conditions. Now we generalize this strategy in a list of steps to follow when solving static equilibrium problems for extended rigid bodies. We proceed in five practical steps.

Photo provided by Flickr

This is a static equilibrium problem where two cables are suspending a mass. The cables are set at equal angles to the horizontal. In this problem both of the cables have a vertical lifting component and share the load equally. You will use trigonometry to solve for the values of the tension on each of the cables.A special case of static equilibrium occurs when all external forces on an object act at or along the axis of rotation or when the spatial extension of the object can be disregarded. In such a case, the object can be effectively treated like a point mass. In this special case, we need not worry about the second equilibrium condition, Equation 12.9, because all torques are identically zero and the first equilibrium condition (for forces) is the only condition to be satisfied. The free-body diagram and problem-solving strategy for this special case were outlined in and . You will see a typical equilibrium situation involving only the first equilibrium condition in the next example.Introduction to Static Equilibrium "Hanging Problems" Details how to solve the problem when the tension in the two cables are unknown. The basic approach can be used to solve any of these types of prolbems.This is a very famous physics homework problem. It deals with static equilibrium where the net torque of the system is zero.

Let me know any other physics problem that you want me to solve.