# Homework Help: The 'natural frequency' of an object. What does this mean?

1. May 1, 2007

### Couperin

What does it mean to say that something, for example a bridge, has a natural frequency? Does this have anything to do with how long it is?

2. May 1, 2007

### Chi Meson

Like a swing in a playground, if you push anything, it will oscillate; that is, it will swing back and forth at a certain rate. This rate is called the natural frequency. All things that are not completely inelastic (like warm clay) will do this. buildings and bridges, bricks, rocks, trees, planets, everything.

3. May 1, 2007

### turdferguson

Its what Tesla supposedly used to build his earthquake machine. Its also the reason why soldiers have to break their march when going across bridges

4. May 1, 2007

### Astronuc

Staff Emeritus
Yes, length is one factor. Other factors include mass and rigidity or stiffness. Structures have natural frequencies, and members or components have their own natural frequencies, and then there are couplings or coupled interactions between components.

from http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/sound/u11l4a.html [Broken]

http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0025332.html

Last edited by a moderator: May 2, 2017
5. May 1, 2007

### Feldoh

Somebody watches mythbusters

6. May 2, 2007

### Couperin

Thank you all very much.