Question

Earth’s gravitational pull on a spacecraft some distance away is 139 N in magnitude. What will be the magnitude of the force (N) of gravity be on a second spacecraft having mass 2.0 times the mass of the first spacecraft, at a distance from earth’s centre that is 0.68 times as greater than first.

Answer 1

SOLUTION:

Let M be the mass of the first spacecraft and R be the distance from earth to first spacecraft.

We know that, Magnitude of Force of gravity between earth and the first spacecraft is given by:

Now, For the second spacecraft:

Given that, Mass of second spacecraft, M₂ = 2M

Distance from the earth to the second spacecraft, R₂ = R + 0.68 R = 1.68 R

Therefore, Magnitude of Force of gravity between earth and the second spacecraft is given by:

Substituting from (1)

From (1), We have, F = 139 N

​​​​​​​