Question

help please!! The drawings show three charges that have the same magnitude but may have different signs. In all cases the distance d between the charges is the same. The magnitude of the charges is |q|= 2.7 μC, and the distance between them is d = 4.5 mm. Determine the magnitude of the net force on charge 2 for each of the three drawings.

Answer 1

the magnitude of the electro-static force between the same charges q when they separated by a distance d is given by the formula , F = Kq^2/d^2
where , K is the electro-static constant = 9x10^9 Nm2/C2
(c)
force on q2 due to q1 is
F21 = (9x10^9 )(2.7x10^-6)^2/(4.5x10^-3)^2
= 3.24 x10^3 (-i) N
simillarly,
force on q2 due to q3 is
F31 = (9x10^9 )(2.7x10^-6)^2/(4.5x10^-3)^2
= 3.24 x103 (-j) N
thus, resultant force ,
F = 3.24 x10^3 (-i) N + 3.24 x10^3 (-j) N
thus, maghnitude of the force is
= 4.58 x10^3N