Question

The weight of an object four earth radii from the center of the earth is:

Answer 1

Answer:

D. 1/16 It's weight on the surface.

Explanation:

As we know that the gravity due to earth at its surface is given as

$g = \frac{GM}{R^2}$

now at the distance of 4 radius of earth the gravity is given as

$g' = \frac{GM}{(4R)^2}$

so we can say that

$g' = \frac{g}{16}$

so here gravity becomes 1/16 times of the gravity due to earth on its surface

now we know that weight on the surface of earth is given as

$W = mg$

also the weight now at the given height is given by

$W' = mg/16$

so here correct answer will be

D. 1/16 It's weight on the surface.