What formula gives the strength of an electric field, e, at a distance from a known source charge? e = e = e = e =

E = kQ/d²

The electric field strength is dependent upon the quantity of charge on the source charge (Q) and the distance of separation (d) from the source charge.

Therefore; electric field strength is given by the formula;

E = kQ/d²;

where E is the electric field strength,

           Q is the quantity of charge on the source charge and

            d is the distance of separation from the source charge

the answer is b, have negligible mass

grav force prop 1/r squared 2r all squared is 4rsquared 1/4rsquared quartered