Question

When a falling meteoroid is 3.4 times the radius of the earth from the Earth's surface, what is its acceleration?

Answer 1

`~~ 0.5 ms^-2`

Explanation:

We can approximate the earth to be a spherically symmetric mass. For such systems, the force of gravitation on an object outside is the same as that will result if the entire mass were at the center.

For a point on the surface, at a distance `R` from the center, the acceleration is 9.8 `ms^-2` .

The meteorite is at `R+3.4R = 4.4R`. The acceleration here is

`9.8 ms^-2 times (R/{4.4R})^2 ~~ 0.5 ms^-2`