Question

Two objects have masses of `3 MG` and `15 MG`. How much does the gravitational potential energy between the objects change if the distance between them changes from `160 m` to `280 m`?

Answer 1

See the explanation below

Explanation:

HINT:

Gravitational potential energy of masses `M_1` & `M_2` separated by a distance `D` is given as

`U_G=-\frac{GM_1M_2}{D}`

Change of gravitational potential energy of masses `M_1` & `M_2` when distance changes from `D_1` to `D_2` such that `D_1<D_2`, is given as

`(U_G)_2-(U_G)_1=-\frac{GM_1M_2}{D_2}-(-\frac{GM_1M_2}{D_1})`

`\Delta U_G=GM_1M_2(1/D_1-1/D_2)`

Now, substitute the corresponding values in above formula to get change in potential energy.