Two point charges are held fixed on the y-axis:negative charge #1, q1 = −6.30 ✕ 10−9C, is located at the origin; charge #2, a positive charge,q2 = +8.30 ✕ 10−9 C, is located atthe point (x=0, y=+4.00✕10−2 m).
Consider the point (x=0, y=−7.00✕10-2 m) on thenegative 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: ke = 8.9876 ✕109 (N m2)/C2.
(a.) What are the x and y-components of theelectric field due to just charge #1, q1, atthe point (x=0, y=−7.00✕10−2 m)? [Pleaseremember to consider direction, and include the appropriate sign toindicate whether each component is in the positive/negativex/y direction.]
x1 =  î N/C
y1 =Â Â
(b.) What are the x and y-components of theelectric field due to just charge #2, q2, atthe point (x=0, y=−7.00✕10−2 m)? [Pleaseremember to consider direction, and include the appropriate sign toindicate whether each component is in the positive/negativex/y direction.]
x2 =  î N/C
y2 =  ĵ N/C
(c.) If a third charge, q3 = +4.00 ✕ 10−9C, is placed at the point (x=0, y=−7.00✕10-2m), what is the magnitude of the electric force onq3 due to charges #1 and #2?
FE =Â Â N
(d.) If the system is now composed of these three charges heldfixed along the y-axis, what is the electric potential,V, at point (x=+4.00✕10-2 m, y=0) onthe positive x-axis? [The three charges on they-axis: q1 at y=0,q2 at y=+4.00 cm, andq3 at y=−7.00 cm.]
V =Â Â V
(e.) What is the change in electric potential energy of the systemif a fourth charge, q4 = +9.00 ✕ 10−9C, is placed at the point (x=+4.00✕10-2 m,y=0)?
ΔUE =  J
