Question

1. The force of +50.0μC at (-10.0m, 0) and +50.0μC at (10.0m, 0) on 20.0μC at (0, 0). Show solution.

2. The force of +40.0μC at (0, -3.00m) and +20.0μC at (0, 3.00m) on 50.0μC at (4.00m, 0). Show solution.

Answer 1

$F=F_{13}-F_{23}=k{q_1q_3}/{r_{13}^2}-kq_2q_3/r_{23}^2=$

$=9\cdot10^9\cdot50\cdot10^{-6}\cdot20\cdot10^{-6}/10^2-$

$-9\cdot10^{-9}\cdot50\cdot 10^{-6}\cdot20\cdot10^{-6}/10^2=0$ . Answer

$F=\sqrt{F_{13}^2+F_{23}^2+2F_{13}F_{23}\cos73.74°}$

$F_{13}=k{q_1q_3}/{r_{13}^2}=$

$=9\cdot10^9\cdot40\cdot10^{-6}\cdot50\cdot10^{-6}/5^2=0.72\ (N)$

$F_{23}=kq_2q_3/r_{23}^2=$

$=9\cdot10^9\cdot20\cdot10^{-6}\cdot50\cdot10^{-6}/5^2=0.36\ (N)$

$F=\sqrt{0.72^2+0.36^2+2\cdot0.72\cdot 0.36\cdot\cos73.74°}=$

$=0.89\ (N)$ . Answer