Two positive point charges are arranged as shown below on a y-axis. The charges

Question

Two positive point charges are arranged as shown below on a y-axis. The charges and there locations are are: q1 = +10.2 nC at (0, 8.80) mm and q2 = +6.0 nC at the origin.

What will be the y coordinate of this point (in mm)? I keep getting weird numbers like 0.44 mm HELP!

Explanation / Answer

x-coordinate of required point = 0 (as shown in part a) y-coordinate of required point = y for the force on q3 to be 0, this y-coordinate must be in between y=8.8 mm and y=0 force on q3 due to q1 = k*q1*q3/r^2 => F31 = 9*10^9*10.2*10^-9*47.2*10^-9/y^2 => F31 = 4.33*10^-6/y^2 force on q3 due to q2 = 9*10^9*47.2*10^-9*6*10^-9/(8.8-y)^2 => F32 = 2.55*10^-6/(8.8-y^2) now, for the net force on q3 to be zero, F31 = F32 => 4.33*10^-6/y^2 = 2.55*10^-6/(8.8-y^2) => 3.81*10^-5 - 4.33*10^-6 *y^2 = 2.55*10^-6*y^2 => y^2 = 5.538 => y = 2.353 mm

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

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