Problem 13.16

กำหนดให้ \(q_{2} = 2.0\times 10^{-3} C, q_{3} = -3.0\times 10^{-4} C , q_{4} = 4.0\times 10^{-4} C\)

และ \(r_{32} = r_{42} = r = 3.0 m\)

จาก \(\vec{F}_{2} = \vec{F}_{32} + \vec{F}_{42}\)

r̂r̂

\(\vec{F}_{2} =\frac{kq_{3}q_{2}}{r_{32}^{2}}_{32} +\frac{kq_{4}q_{2}}{r_{42}^{2}}_{42}\)

îĵ

\(\vec{F}_{2} =\frac{k}{r^{2}}(|q_{2}||q_{3}| - |q_{2}||q_{4}| )\)

îĵ

\(\vec{F}_{2} = 600 - 800 N\)

\(|\vec{F}_{2}| =\sqrt{(600)^{2} + (-800)^{2}}\)

\(|\vec{F}_{2}| = 1.0 kN \;\blacksquare\)