1. Two charges of 6 × 109 C and 2.1 × 109 C are separated by a distance of 42 cm

Question

1. Two charges of 6 × 109 C and 2.1 × 109 C are separated by a distance of 42 cm. Find the equilibrium position for a third charge of +1.2 × 108 C by identifying its distance from the first charge q1. Answer in units of cm.

2.A charge of +1 Coulomb is place at the 0 cm mark of a meter stick. A charge of +4 Coulombs is placed at the 100 cm mark of the same meter stick. Where should a proton be placed on the meter stick so that the net force on it due to the two charges is 0? Answer in units of cm.

3.What is the angle between the electrostatic force on the charge at the origin and the positive x-axis? Answer in degrees as an angle between 180 and 180 measured from the positive x-axis, with counterclockwise positive. Answer in units of .

Explanation / Answer

For equilibrium of third charge:

F13 = F23

k q1q3/r13^2 = k q2q3/r23^2

q1/r13^2 = q2/r23^2

q1/q2 = (r13/r23)^2

r13/r23 = sqrt(q1/q2)

r13/r23 = sqrt(6 x 10^-9/2.1 x 10^-9) = 1.69

r13 = 1.69 r23

r13 + r23 = 42

1.69 r23 + r23 = 42 => r23 = 15.61 cm

r13 = 1.69 x 15.61 = 26.37 cm

Hence, r13 = 26.37 cm (from the first charge)

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

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