When a test charge of +8 nC is placed at a certain point, the force that acts on it has a magnitude of 0.128 N and is directed northeast.
(a) If the test charge were -4 nC instead, what force would act on it? What magnitude (N) and what direction (northeast, northwest, southeast, southwest)?
(b) What is the electric field at the point in question? What magnitude (N/C) and what direction (northeast, northwest, southeast, southwest)?