Question

A intensidade do campo elétrico, num ponto situado a 3,0 mm = (3x10-3m) de uma carga elétrica puntiforme Q = 4 μC = (4x10-6 C) no vácuo (ko = 9x109 N.m2/C2) é:

Answer 1

$d = 3,0 \cdot 10^{-3}\\Q = 4,0 \cdot 10^{-6}C\\k_0 = 9,0 \cdot 10^9Nm^2/C^2\\\\E = \frac{k_0Q}{d^2}\\E = \frac{9\cdot 10^9 \cdot 4 \cdot 10^{-6}}{(3 \cdot 10^{-3})^2}\\E = \frac{36 \cdot 10^3}{9\cdot 10^{-6}}\\E = 4 \cdot 10^{3 + 6}\\\boxed{E = 4,0 \cdot 10^9N/C}$