Two particles, with charges of 60.0 nC and -60.0 nC, are placed at the points wi

Question

Two particles, with charges of 60.0 nC and -60.0 nC, are placed at the points with coordinates (0, 4.00) cm and (0, -4.00) cm as shown in Figure P25.28. A particle with charge 30.0 nC is located at the origin.

particles, with charges of 60.0 nc and are placed at the points with coordinates (0, 4.00) cm and (0, 4.00) cm as shown in Figure P25.28 with A particle with charge 30.0 nc is located at the origin (a) Find the electric potential energy of the configuration of the three fixed charges 2.44e5 The response you submitted has the wrong sign. J 2.22 x 10 13 kg and a charge of 120.0 (b) A fourth particle, with a mass of nc, is released from rest at the point (3.00, 0) cm. Find its speed after it has moved freely to a very large distance away. 2.44e5 Your response differs from the correct answer by more than 100%, m/s

Explanation / Answer

a)

electric potential energy is given as

U = k QQ'/BC + kQq/AB + kQ'q/AC

U = (9 x 109) (60 x 10-9) (- 60 x 10-9)/(0.04 + 0.04) + (9 x 109) (60 x 10-9) (30 x 10-9)/(0.04) + (9 x 109) (- 60 x 10-9) (30 x 10-9)/(0.04)

U = - 0.000405 J

b)

electric potential at the location of fourth charge due to two charge on Y-axis would be 0 since they have equal and opposite charge and are at same distance from fourth charge. hence electric potential by them cancel out

electric potential is only due to charge at origin

using conservation of energy

electric potential energy of fourth charge = kinetic energy

kq q4 /r = (0.5) m v2

(9 x 109) (30 x 10-9) (120 x 10-9)/(0.03) = (0.5) (2.22 x 10-13) v2

v = 9.86 x 104 m/s

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

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