A particle of charge 2.0 x 10⁻⁸C experiences an upward force of magnitude 4.0 x10⁻⁶ when it is placed in a particular point in an electric field.
a. What is the electric field at that point?
b. If a charge q=1.0 x 10⁻⁸ C is placed there, what is the force on it?