Two objects have masses of 9 MG9MG and 5 MG5MG. How much does the gravitational potential energy between the objects change if the distance between them changes from 24 m24m to 48 m48m?

1 Answer
Apr 6, 2018

The gravitational energy will change by =0.9375*10^-5J=0.9375105J

Explanation:

Gravitational potential is the potential energy per kilogram at a point in a field.

So the units are J, "Joules"J,Joules

Phi=-G(M_1M_2)/R

The gravitational universal constant is

G=6.67*10^-11Nm^2kg^-2

The masses causing the field is =M_1 kg and =M_2 kg

The mass is M_1=9MG=9*10^6g=9*10^3kg

The mass is M_2=5MG=5*10^6g=5*10^3kg

The distance between the centers is =Rm

The distance R_1=24m

The distance R_2=48m

Therefore,

Phi_1=(-G*(9*10^3*5*10^3)/24)

Phi_2=(-G*(9*10^3*5*10^3)/48)

So,

Phi_1-Phi_2=(-G*(9*10^3*5*10^3)/24)-(-G*(9*10^3*5*10^3)/48)

=9*5*10^6*6.67*10^-11(1/48-1/24)

=-0.9375*10^-5J