• Question: what is the weight of the world

    Asked by michael to Ahmed, Francesca, George, James, Nitheen on 13 Nov 2014.
    • Photo: James Sullivan

      James Sullivan answered on 13 Nov 2014:

      Hi Michael,

      according to google it’s 5972000000000000000000000 kg

    • Photo: Ahmed Osman

      Ahmed Osman answered on 16 Nov 2014:

      Dear Michael,
      According to Newton’s equation and his assumption that for spherical objects, you can make the simplifying assumption that the entire object’s mass is concentrated at the centre of the sphere. So mass of the Earth is 6,000,000,000, 000,000,000,000,000 kilograms (6 x 1024 kilograms, or 1.3 x 1025 pounds)
      It is “more proper” to ask about mass rather than weight because weight is a force that requires a gravitational field to determine. You can take a bowling ball and weigh it on the Earth and on the moon. The weight on the moon will be one-sixth that on the Earth, but the amount of mass is the same in both places. To weigh the Earth, we would need to know in which object’s gravitational field we want to calculate the weight. The mass of the Earth, on the other hand, is a constant.
      I hope this answer is clear