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Re: Calculating G

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Op 30-dec-2016 om 07:22 schreef Peter Riedt:
> On Friday, December 30, 2016 at 11:03:06 AM UTC+8, Gary Harnagel wrote:
>> On Thursday, December 29, 2016 at 6:31:08 PM UTC-7, Peter Riedt wrote:
>>>
>>> Calculating G
>>>
>>> The constant G was anticipated by Newton but first accurately determined in
>>> the laboratory by Henry Cavendish in 1798. It has the value
>>> G=6.674E-11m3kg−1s−2 (cubic meters per kilogram second squared).
>>>
>>> G can be derived from elements of a star by the formula G=gstar*rstar^2/Mstar
>>>
>>> 	  gstar	   rstar	   Mstar	    G	
>>> Sun	 273.97	696,000,000	 1.99E+30	6.674E-11	
>>> ACa	 200.18	853,992,000	 2.19E+30	6.674E-11	
>>> ACb	 332.10	602,040,000	 1.80E+30	6.674E-11	
>>> AC c	1695.00	 98,136,000	 2.45E+29	6.674E-11	
>>>
>>> gstar = surface acceleration in m/sec
>>> rstar = radius in m
>>> Mstar = mass in kg
>>
>> SO how was g determined for each of these stars?
>>
>>> G can also be derived from g, radius and mass of the planets by the formula
>>> G=gpl*rpl^2/mpl
>>>
>>> 	  gpl	   rpl(m)	    mpl	    G	
>>> MER 	 3.71	 2,439,000	3.30E+23	6.674E-11	
>>> VEN 	 8.87	 6,051,602	4.87E+24	6.674E-11	
>>> EAR 	 9.80	 6,378,621	5.97E+24	6.674E-11	
>>> MAR 	 3.71	 3,397,360	6.42E+23	6.674E-11	
>>> JUP 	24.79	71,499,344	1.90E+27	6.674E-11	
>>> SAT 	10.44	60,273,223	5.68E+26	6.674E-11	
>>> URA 	 8.87	25,556,472	8.68E+25	6.674E-11	
>>> NEP 	11.15	24,765,365	1.02E+26	6.674E-11	
>>> PLU 	 0.62	 1,158,753	1.25E+22	6.674E-11	
>>>
>>> gpl = surface acceleration of a planet
>>> rpl = radius of a planet
>>> mpl = mass of a planet
>>>
>>> The calculated G numbers of the Sun, Alpha Centauri A, B and C and nine
>>> planets are identical with the Codata value of G=6.674E-11.

And you went to visit these planets to measure the gpl-values, right.

>>
>> That's probably because G was used to determine g :-)
>
> Alpha Centauri A B C have their g values on the Internet in the form log g.

And the Internet went there to measure them, right.

Dirk Vdm

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Re: Calculating G Gary Harnagel <hitlong@yahoo.com> - 2016-12-29 19:02 -0800
  Re: Calculating G Peter Riedt <riedt1@yahoo.co.uk> - 2016-12-29 22:22 -0800
    Re: Calculating G Dirk Van de moortel <dirkvandemoortel@hotspam.not> - 2016-12-30 12:13 +0100
      Re: Calculating G Sylvia Else <sylvia@not.at.this.address> - 2016-12-30 22:35 +1100
        Re: Calculating G Dirk Van de moortel <dirkvandemoortel@hotspam.not> - 2016-12-30 13:03 +0100
          Re: Calculating G mlwozniak@wp.pl - 2016-12-30 04:11 -0800
        Re: Calculating G Peter Riedt <riedt1@yahoo.co.uk> - 2016-12-30 14:32 -0800
          Re: Calculating G Gary Harnagel <hitlong@yahoo.com> - 2016-12-30 15:17 -0800
            Re: Calculating G Peter Riedt <riedt1@yahoo.co.uk> - 2016-12-30 16:51 -0800
              Re: Calculating G Sylvia Else <sylvia@not.at.this.address> - 2016-12-31 12:48 +1100
                Re: Calculating G Peter Riedt <riedt1@yahoo.co.uk> - 2016-12-30 19:31 -0800
                Re: Calculating G Sylvia Else <sylvia@not.at.this.address> - 2016-12-31 14:36 +1100
                Re: Calculating G Peter Riedt <riedt1@yahoo.co.uk> - 2016-12-30 23:15 -0800
                Re: Calculating G Sylvia Else <sylvia@not.at.this.address> - 2016-12-31 19:29 +1100
                Re: Calculating G Peter Riedt <riedt1@yahoo.co.uk> - 2016-12-31 01:18 -0800
                Re: Calculating G Sylvia Else <sylvia@not.at.this.address> - 2016-12-31 20:29 +1100
                Re: Calculating G Peter Riedt <riedt1@yahoo.co.uk> - 2016-12-31 19:06 -0800
                Re: Calculating G Alan Folmsbee <omnilobe@gmail.com> - 2016-12-30 21:33 -0800
              Re: Calculating G Gary Harnagel <hitlong@yahoo.com> - 2016-12-30 19:41 -0800
                Re: Calculating G Peter Riedt <riedt1@yahoo.co.uk> - 2016-12-30 23:17 -0800

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