Question

Two point charges are held fixed on the y-axis: negative charge #1, q₁ = −6.30 ✕ 10⁻⁹ C, is located at the origin; charge #2, a positive charge, q₂ = +8.30 ✕ 10⁻⁹ C, is located at the point (x=0, y=+4.00✕10⁻² m).

Consider the point (x=0, y=−7.00✕10^-2 m) on the negative y-axis for parts (a.), (b.), and (c.). Additionally, consider the point (x=+4.00✕10^-2 m, y=0) on the positive x-axis for parts (d.) and (e.).
Recall, Coulomb's constant: k_e = 8.9876 ✕ 10⁹ (N m²)/C².

(a.) What are the x and y-components of the electric field due to just charge #1, q₁, at the point (x=0, y=−7.00✕10⁻² m)? [Please remember to consider direction, and include the appropriate sign to indicate whether each component is in the positive/negative x/y direction.]
_x1 =  î N/C
_y1 =  

(b.) What are the x and y-components of the electric field due to just charge #2, q₂, at the point (x=0, y=−7.00✕10⁻² m)? [Please remember to consider direction, and include the appropriate sign to indicate whether each component is in the positive/negative x/y direction.]
_x2 =  î N/C
_y2 =  ĵ N/C

(c.) If a third charge, q₃ = +4.00 ✕ 10⁻⁹ C, is placed at the point (x=0, y=−7.00✕10^-2 m), what is the magnitude of the electric force on q₃ due to charges #1 and #2?
F_E =  N

(d.) If the system is now composed of these three charges held fixed along the y-axis, what is the electric potential, V, at point (x=+4.00✕10^-2 m, y=0) on the positive x-axis? [The three charges on the y-axis: q₁ at y=0, q₂ at y=+4.00 cm, and q₃ at y=−7.00 cm.]
V =  V

(e.) What is the change in electric potential energy of the system if a fourth charge, q₄ = +9.00 ✕ 10⁻⁹ C, is placed at the point (x=+4.00✕10^-2 m, y=0)?
ΔU_E =  J

Answer 1