Question 1153048
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...,  the weight of an object is inversely proportional to the square of its distance from the centre of the earth. 
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d, distance from center
w, weight of object
k, variation constant


{{{w=k/d^2}}}

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{{{k=w*d^2}}}



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 If a person weighs 190 lb on the surface of the earth (assume this to be 3960 mi from the centre),...
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{{{k=190*3960^2}}}

{{{k=2979504000}}}


Model equation is   {{{highlight_green(w=2979504000/d^2)}}}.


Your question has  {{{d=3960+1800}}}.
{{{w=2979504000/(3960+1800)^2}}}