Question

A 30 nC point charge is positioned at the origin and a -20 nC point charge is positioned on the x-axis at 1.0 m. Take the electric potential to be zero at infinity. To three significant figures, determine: a) the electric potential on the x-axis at 0.5 m. (1 pt) b) the electric potential on the x-axis at 1.5 m. (1 pt) c) the electric potential energy stored between the charges. (1 pt)

please help me

Answer 1

charge q1 = 30 nC = 30 x 10^-9 C

charge q2 = -20 nC = - 20 x 10^-6

distance between two charges, r = 1 m

a)

electric potential at a point at x = 0.5 m is V = potential due to q1 + potential due to q2

V = 1/4πε₀ q1/0.5 + 1/4πε₀ q2/0.5 = 9 x 10⁹ x 30 x 10^-9 /0.5 - 9 x 10⁹ x 20 x 10^-9 /0.5

V = 180 v

electric potential at a point at x = 0.5 m is V = 180 V

b)

electric potential at a point at x = 1.5 m is V = potential due to q1 + potential due to q2

V = 1/4πε₀ q1/1.5 + 1/4πε₀ q2/0.5 = 9 x 10⁹ x 30 x 10^-9 /1.5 - 9 x 10⁹ x 20 x 10^-9 /0.5

V = -180 v

electric potential at a point at x = 1.5 m is V = -180 V

c)

potential energy stored between the charges, U = 1/4πε₀ q1 q2/r

U = 9 x 10⁹ x 30 x 10^-9 x -20 x 10^-9 /1 = -5.4 x 10^-6 J

potential energy stored between the charges, U = -5.40 x 10^-6 J