The Naked Scientists

The Naked Scientists Forum

Author Topic: How did scientists calculate the mass of the Earth and Sun  (Read 1283 times)

Offline syhprum

  • Neilep Level Member
  • ******
  • Posts: 3823
  • Thanked: 19 times
    • View Profile
I could not resist this follow up from the previous question "How did scientists calculate the radius of the Earth and Sun"


 

Offline Soul Surfer

  • Neilep Level Member
  • ******
  • Posts: 3345
  • keep banging the rocks together
    • View Profile
    • ian kimber's web workspace
How did scientists calculate the mass of the Earth and Sun
« Reply #1 on: 09/06/2010 08:44:16 »
A set of experiments was done on earth to measure the gravitational attractions between balls of various masses.  This defined the gravitational constant which was found to be the same fro an equal mass of any material.

The distances and orbital periods of the earth moon and sun have been known from earlier measurements and therefore using Newtons law of gravitation and the gravitational constant it is possible to calculate the masses of the earth moon and sun.
« Last Edit: 09/06/2010 08:46:08 by Soul Surfer »
 

Offline graham.d

  • Neilep Level Member
  • ******
  • Posts: 2208
    • View Profile
How did scientists calculate the mass of the Earth and Sun
« Reply #2 on: 09/06/2010 10:23:50 »
If I have done the maths right:

Mass of the sun = ω*r/G

Where r is distance from sun to planet and ω is angular speed (= 2πf)
 

The Naked Scientists Forum

How did scientists calculate the mass of the Earth and Sun
« Reply #2 on: 09/06/2010 10:23:50 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums