Question

how far should a man go away from the center of the earth such that his weight is 1/4 that n the earth radius of the earth is 6400km​

Answer 1

Assuming mass remains constant,

The weight becomes one-fourth.

G = (gravitational constant*m1*m2) ÷ r^2

Now, r = 2r,

G = (gravitational constant*m1*m2) ÷ (2r)^2

Or, G = (gravitational constant*m1*m2) ÷ 4*r^2

Or, (1/4) * [(gravitational constant*m1*m2)÷ r^2]