If the potential created at the point P by the first charge is 5 V, and the electric potential created by the second charge is 2 V, as the potential is proportional to the electric field created by the charges, which is linear (due to it is directly proportional to the value of the charges), we can apply the superposition principle.
In this way, we can calculate the total potential, at a point P, as the algebraic sum of the potentials created by all the charges, as if the other ones were not present.
It may be seen as a statement about inertia, that objects will remain in their state of motion unless a force acts to change the motion. Any change in motion involves an acceleration, and then Newton's Second Law applies.
Your weight will be less than on Earth because in space there is no or very less gravitational pull. There are no planets forming any magnetic fields for other objects to be attracted to.
The type of stars in the areas give different colors to the galactic disk. The galactic disk appears blue because it has a large proportion of young, hot, main-sequence stars. The galactic bulge appears red because it contains many red giants and supergiants. The reddish hue of the galactic bulge indicates that new stars aren't being formed there.