Two point charges, q1--1.7 C and q2 = 1.7 C, are placed on the x axis at X1-3.2

Question

Two point charges, q1--1.7 C and q2 = 1.7 C, are placed on the x axis at X1-3.2 m and X2-_3.2 m, respectively (see figure below. 92 91 %2,0)0x, 0) (a) What are the electric potentials at the points P (0, 3.2 m) and R (6.4 m, 0)? (b) Find the work done in moving a 1.0-uC charge from P to R along a straight line joining the two points. (c) Is there any path along which the work done in moving the charge from P to R is less than the value from part (b)? Explain. O Yes, because the work done depends only on the length of the path chosen. No, because the work done depends only on the change in potential. No, because the work done doesn't depend on the change in potential O Yes, because the change in potential will vary depending on the path chosen.

Explanation / Answer

a)The potentials at the given point will be the sum of individual potentials.

Vp = V1 + V2

Vp = k q1/r1 + k q2/r2

Vp = k (q1/r1 + q2/r2)

r1 = sqrt(3.2^2 + 3.2^2) = 4.53 m

r2 = sqrt(3.2^2 + 3.2^2) = 4.53 m

Vp = 9 x 10^9 [-1.7 x 10^-6/4.53 + 1.7 x 10^-6/4.53] = 0 V

Hence, Vp = 0 V

b)Vr = V1 + V2

Vr = k q1/r1 + k q2/r2

Vr = k (q1/r1 + q2/r2)

r1 = 6.4 - 3.2 = 3.2 m

r2 = 6.4 + 3.2 = 9.6 m

Vr = 9 x 10^9 (-1.7 x 10^-6/3.2 + 1.7 x 10^-6/9.6) = -3187.5

Hence, Vr = -3187.5 V

b)W = q (Vr - Vp)

W = 1 x 10^-6 (-3187.5 - 0) = -3.188 x 10^-3 J

Hence, W = -3.188 x 10^-3 J

c)No, because work done depends on the change in potential.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.