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    Help with the gravitation question please

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    The gravitational field strength is proportional to the product of density and radius. Does this help?

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    This is because g=\frac{GM}{r^2} and M=DV and V=\frac{4 \pi r^3}{3}
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    (Original post by Mr M)
    The gravitational field strength is proportional to the product of density and radius. Does this help?

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    This is because g=\frac{GM}{r^2} and M=DV and V=\frac{4 \pi r^3}{3}
    thanks that was a bit helpful
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    (Original post by Beamchain)
    thanks that was a bit helpful
    Just a bit?!
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    1st calculate the volume (1.6x10^7)^3 x 4pi/3 = 1.715x10^22
    now times by 3000 to get mass = 5.14x10^24
    g=((6.67x10^-11)x(5.14x10^24))/((1.6x10^7)^2) = 13.4N/kg
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    (Original post by shahbaz)
    1st calculate the volume (1.6x10^7)^3 x 4pi/3 = 1.715x10^22
    now times by 3000 to get mass = 5.14x10^24
    g=((6.67x10^-11)x(5.14x10^24))/((1.6x10^7)^2) = 13.4N/kg
    It isn't necessary to make any calculations to obtain the correct answer.
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    (Original post by Mr M)
    It isn't necessary to make any calculations to obtain the correct answer.
    Why not?
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    (Original post by shahbaz)
    Why not?
    Because the product of density and radius is the same for both planets.
 
 
 
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