Physics Forums

Physics Forums (http://www.physicsforums.com/index.php)
-   Classical Physics (http://www.physicsforums.com/forumdisplay.php?f=61)
-   -   Energy Stored in a spring (http://www.physicsforums.com/showthread.php?t=662013)

GeneralOJB Jan2-13 05:05 AM

Energy Stored in a spring
 
Why is the energy stored in a spring 1/2 * distance * force? Isn't work just force * distance?

jbriggs444 Jan2-13 05:42 AM

Re: Energy Stored in a spring
 
Quote:

Quote by GeneralOJB (Post 4215587)
Why is the energy stored in a spring 1/2 * distance * force? Isn't work just force * distance?

The full force is not applied for the full distance.

In the simple case of a constant force over a fixed distance you can just multiply force by distance. But in the case of a spring being compressed, the force is not constant.

You could approximate the answer by analyzing the situation in small steps... You compress the spring the first 1/10th of the distance using 1/10th of the full force, the next 1/10th of the instance using 2/10th of the total force and so on. This approach would give you an answer that is pretty close.

An exact answer can be obtained by using calculus and integrating instantaneous force over incremental distance. That answer turns out to be 1/2 * distance * maximum-force

GeneralOJB Jan2-13 05:53 AM

Re: Energy Stored in a spring
 
Thanks, I understand now.


All times are GMT -5. The time now is 01:08 PM.

Powered by vBulletin Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
© 2014 Physics Forums