Question

find the weight of an object at a height of 6400km above the earth's surface. he weight of the body on the surface of the body is 20n and radius of the earth is 6400km

Answer 1

The equation is: F=−Gm1m2r2 and we know at r=rearth that F = 20 N. If we double r, then the value of F will fall by a factor of 4 ( F∝1r2) so the weight will be 5 N. Incidentally, at the altitude of the international space station (408 km) the value of g=9.81ms2 down here, is only about 7% lower