# Homework Help: Young modulus

1. Jan 5, 2010

### The Dude 321

I simply do not understand what the young modulus is.

Help on properties of solids such as ductility and malleability would help!

2. Jan 5, 2010

3. Jan 6, 2010

### The Dude 321

I am currently doing A level physics. I do not understand searle's apparatus.

I do not understand the significance of young modulus.

4. Jan 6, 2010

### vertices

It's just a ratio of the tensile stress/strain. Its kind of like a measure of the wire's stiffness.

The tensile stress is the force that is applied, perpendicular to the wire's cross section. The strain is simply the amount the wire extends by (beyond its natural length) divided by its natural (original) length.

5. Jan 6, 2010

### Astronuc

Staff Emeritus
I'm somewhat puzzled here. One know about a Searle's apparatus, but one does not understand it's function? Is this not covered in class or in one's textbook?

There is a relevant discussion here - http://en.wikibooks.org/wiki/A-level_Applied_Science/Choosing_and_Using_Materials/Properties

Young's modulus is the coefficient that represents the amount of stress per unit strain when a material is 'elastically' deformed. The elastic range proceeds from no load (0 stress) to the 'yield stress'. When a material yields, it undergoes plastic (permanent) deformation.

Ductility relates to the elongation or stretching (under a tensile load) without breaking. The greater the material, the more ductile it is.

Malleability is somewhat related, but it has to do with the ability of a material to be deformed under compression without breaking or cracking.