# What is the force, in terms of Coulomb's constant, between two electrical charges of -7 C and 4 C that are 3 m  apart?

Jan 30, 2016

$2.8 \times {10}^{8} N$

#### Explanation:

we know,
$F = \frac{1}{4 \pi {\epsilon}_{\circ}} \frac{{q}_{1} {q}_{2}}{d} ^ 2$

$= 9 \times {10}^{9} \frac{- 7 \cdot 4}{3} ^ 2$

$= \cancel{9} \times {10}^{9} \frac{- 28}{\cancel{9}}$

$= - 2.8 \times {10}^{8} N$