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Re: Accessing and using built-in constants in Mathematica 6 / precision

• To: mathgroup at smc.vnet.net
• Subject: [mg86501] Re: Accessing and using built-in constants in Mathematica 6 / precision
• From: dh <dh at metrohm.ch>
• Date: Wed, 12 Mar 2008 05:28:10 -0500 (EST)
• References: <fr7oj6$32k$1@smc.vnet.net>

Hi,

ElementData gives the AtomicWeight to 6 digits. I do not know if this is 

  because it is not more precisely known, but for everyday use, this is 

should be precise enough.

To get SpeedOfLight you need first to load the package PhysicalConstants:

<< PhysicalConstants`

SpeedOfLight

hope this helps, Daniel





ratullochjk2 at gmail.com wrote:

> Accessing and using built-in constants in Mathematica 6 / precision

> tia sal2

> 

> Greetings all

> 

> Sorry if this is a repeat post my last post didn't show up in the

> newsgroups

> 

> I can access the constants for the elements with no problem

> Example:

> In[1]:= ElementData["C", "AtomicWeight"]

> Out[2]:= 12.0107

> 

> 1) I'm trying to use the built in constants for

> speed of light, Plank's constant, etc.. but I'm having problems

> finding them / the proper syntax.

> 

> 2) Also How do I increase the amount of the decimal places?

> Example:

> elementatomicW := ElementData["C", "AtomicWeight"]

> << Units`

> Convert[elementatomicW AMU, Kilogram]

> The answer is 1.99443*10^-26 Kilogram

> 

> I add N like it says but the answer still comes out the same

> Example:

> << Units`

> N[Convert[elementatomicW AMU, Kilogram], 20]

> 

> tia sal2

>