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While reading gravitation chapter I

  1. Sep 3, 2010 #1
    While reading gravitation chapter I got some doubts, and that I am posting here.

    1) Is there any meaning of "Weight of the Earth"?

    2)At noon, the sun and the earth pull the objects on the earth's surface in opposite direction. At midnight the sun and the earth pull these objects in the same direction. Is the weight of an object as measured by the spring balance on the earth's surface more at midnight as compared to its weight at noon?

    3)An apple falls from a tree. An insect in the apple finds that the earth is falling towards it with an acceleration g. Who exerts the force needed to accelerate the earth with this acceleration g?

    4)A nut becomes loose and gets detached from a satellite revolving around the earth. Will it land on earth? If yes then where? If no, how can an astronaut make it land on the earth?

    5)Is it necessary for the plane of the orbit of a satellite to pass through the centre of the earth?

    6)As earth rotates about its axis, a person living in his house at the equator goes in a circular obit of radius equal to the radius of the earth. Why does he/she not feel weightlessness as a satellite passenger feels?
  2. jcsd
  3. Sep 3, 2010 #2
    Re: Gravitation

    I think it has, but it will be different for different planets and stars since they have different masses, so they'll be attracting earth towards themselves with different magnitude of force because,

    g(acceleration due to gravity) = √GM/R2, where M & R are the mass and the radius of the body that is attracting earth towards itself and

    weight of earth will differ man-to-man

    for a man of mass 50 kg, weight of earth is 50g N for a man of weight 60kg weight of earth is 60g N (if weight is force with which the man attracts the earth toward's his centre of gravity
    Last edited: Sep 3, 2010
  4. Sep 3, 2010 #3
    Re: Gravitation

    Well the nut will land or not on the earth depends on where it is located, it will surely land on the earth if its inside the satellite( yeah I agree that, for that satellite too has to land on the earth). It is also depended on where satellite is located, if it is located far away from the earth and the nut is out side it and where the gravitational force is only optimum may be then nut will fly off in the space.

    Don't know how will astronaut will make it land on earth. :P:P So please help. :)
  5. Sep 3, 2010 #4
    Re: Gravitation


    the force exerted is the pseudo force
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