Question

1. what is the magnitude of the force on a charge of +2×10^-7 C that is 0.3 from a charge of -5×10^{-7 C?}

Answer 1

$F=|\frac{kq_1q_2}{r^2}|,$

$F=\frac{9\cdot 10^9\cdot 2\cdot 10^{-7}\cdot 5\cdot 10^{-7}}{0.3^2\cdot 10^{-4}}=100~N.$