Gravity is the only one helping it.
Answer:
d) 0 V
Explanation:
It can be showed that the potential due to a point charge q, to a distance d from the charge, can be expressed as follows:

where k = 
As the potential is an scalar, and is linear with the charge, we can apply the superposition principle, which means that we can find the potential due to one of the charges, as if the other were not present.
By symmetry, all four charges are at the same distance from the center, so we can write the total potential, as follows:

where d, is the semi-diagonal of the square, that we can find applying Pythagorean theorem, as follows:

Replacing by the values in (1) we have:

which is equal to the option d).
If I tell you that I traveled 30 miles in the last 2 hours, the only thing you can calculate is my average speed during those two hours. You can't tell anything about my acceleration or the direction in which I traveled.
True or False. The answer to the question
The equation you would use here is F=ma, where F is the force in Newtons, m is the mass in kilograms (must be in kilograms in order for the units to match on both sides), and a is acceleration in meters per second squared. Therefore, you do: 65kg x .3m/s^2= FF. That'll give you the answer.