Question

Two point charges, each +2.00 nC, are separated by 10 mm. (4 parts)

A) What is the force between the two charges? Is it attractive or repulsive?

B) What is the strength and direction of the electric field due to ONE of the charges, 5.00 mm away from the charge?

C) What is the strength of the total electric field halfway between the two charges?

D) If a -3.00 nC charge were places halfway between the two charges, what would happen go it? In other words, toward which charge would it move? Explain your answer.

Answer 1

(A) Since both charges are of same polarity therefore they will repel each other.
(B) Electric field due to one charge
E = Kq/r²   where K is constant = 9*10⁹ , q is charge = 2nC and r is the distance = 5 mm
E = (9*10⁹*2*10^-9)/(5*10^-3)² = 7.2*10⁵ N/C
(C) Since both the charge are of equal magnitude therefore they have same electric field at the halfway i.e. 5 mm
but in the opposite direction therefore the net or total electric field is ZERO.
(D) Since the force applied by the both charges on the -3nC charge will be equal and opposite therefore it will
not move from its place.