Respostas

2014-06-03T06:47:42-03:00
Lei de coulomb :

Fel =  \frac{K.q.q}{d^2}

K~> constante = 9.10⁹ N.m²/c²

90 cm = 0,9 m

FICA

9.10^-^1 = \frac{9.10^9.q.q}{(0,9^2}

0,729 = 9.10^9.q^2

\frac{0,729  }{9.10^9} = q^2

81.10^-^1^2 = q^2


q=  \sqrt{81.10^-^1^2 } =9.10^-^6 C

ou 9 μC