Meters per second squared:

If you think about it, acceleration is about how fast speed changes. Speed is measured in meters per second:

So if you take that and just measure it over time, you get meters per second squared.
The electrical force between these two charges remains the
same. In coulomb’s law, it states that the magnitude of two charges (product of
two charges) is inversely proportional to the square of the distance. Since both
the magnitude and the distance are halved, therefore, the change in both quantities
will have no effect in the value of electrical force.
You might want to do a re-erp on this equation