# Two charges of  -1 C  and  4 C  are at points  (-2 ,1,8 )  and  ( 1,4,-2), respectively. Assuming that both coordinates are in meters, what is the force between the two points?

Oct 7, 2017

$3.05 \cdot {10}^{8} N$

#### Explanation:

Distance between points $\to \sqrt{118}$ (source)

According to Coulomb's law,

$F = k \times \frac{\left\mid {q}_{1} \right\mid \times \left\mid {q}_{2} \right\mid}{{r}^{2}}$

$\implies F = \left(9 \cdot {10}^{9} {\text{N""m"^2/"C}}^{2}\right) \frac{\left\mid - 1 C \right\mid \times \left\mid 4 C \right\mid}{{\left(\sqrt{118 m}\right)}^{2}}$

$\implies F = \left(9 \cdot {10}^{9} {\text{N"cancel("m"^2)/cancel("C"^2))times4cancel("C"^2)/cancel("m}}^{2}\right)$

$\implies F \approx 305084745 N \text{ OR } 3.05 \cdot {10}^{8} N$