- #1
Zouatine
- 22
- 0
Hi! hope you are doing well ,
I'm trying to solve this problem ( mechanical problem) about structure with load F as it showing in the next figure , i want to determine to critical force F , the stability force ( which means if my load is bigger than the critical load my system will be unstable) ,so to get i have to do by Energy method which means i have to use potential ,in this step i have some questions :
1- why the External Energy must be with negative sign ?
2 - what does mean the total potential is Stationary ?
I'm trying to solve this problem ( mechanical problem) about structure with load F as it showing in the next figure , i want to determine to critical force F , the stability force ( which means if my load is bigger than the critical load my system will be unstable) ,so to get i have to do by Energy method which means i have to use potential ,in this step i have some questions :
1- why the External Energy must be with negative sign ?
2 - what does mean the total potential is Stationary ?
![&é.JPG &é.JPG](https://www.physicsforums.com/data/attachments/240/240146-c8814ba2a0994a86879dd6c208bef7ec.jpg)