Are the Material Properties in My Physics Library Accurate?

AI Thread Summary
The discussion centers on the accuracy of material properties in a physics library for an application, specifically focusing on density, friction, and restitution values for various materials like wood, iron, concrete, rubber, polystyrene, and plastic. It is noted that coefficients of friction and restitution are not intrinsic properties, as they can vary significantly based on conditions and specific material types. For example, rubber's friction can change depending on the surface it interacts with, and wood properties can differ widely among species. The accuracy of these values is questioned, suggesting that they may not need to be precise due to inherent variability. Overall, the discussion emphasizes the contextual nature of these material properties.
RicardoTk
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Hi everyone!

Im developing an application with a physics library.

In the application I pre-setted some materials with the following properties,

Density, Friction and Restitution

Im not sure if this informations are truly trustable,

Can you guys just review this for me?

===|Wood|==
Density: 680 kg/m³
Friction: 0.4
Restitution: 0.7

===|Iron|==
Density: 7400 kg/m³
Friction: 1 (Steel = 0.8 )
Restitution: 0.85

===|Concrete|==
Density: 2300 kg/m³
Friction: 0.65
Restitution: 0.75

===|Rubber|==
Density: 920 kg/m³
Friction: 0.75
Restitution: 0.3

===|Polystyrene|==
Density: 80 kg/m³
Friction: 0.5
Restitution: 0.5

===|Plastic|==
Density: 1300 kg/m³
Friction: 0.35
Restitution: 0.6

References:
http://www.matbase.com/
http://www.matweb.com/
http://physics.info/density/
http://www.bulletphysics.org/Bullet/php ... ?f=9&t=616
http://www.woodweb.com/knowledge_base/W ... dbook.html
http://www.engineershandbook.com/Tables ... cients.htm
http://www.engineeringtoolbox.com/frict ... d_778.html
http://hypertextbook.com/facts/2006/restitution.shtml

Thanks!
 
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I can't tell you if these values are correct, but the coefficient of friction and (probably) the coefficient of restitution are not intrinsic properties of the materials. Think about it, the same rubber tires will stop in a shorter distance on dry asphalt than on wet, and a basketball will bounce higher on cement than on shag carpeting.
 
How accurate do they need to be because the properties for wood vary by a factor of at least 2 depending on species.
 
Thank you guys! :cool:
 

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