# A charge of 2 C is at (5, 2) and a charge of -1 C is at ( 2, -9 ). If both coordinates are in meters, what is the force between the charges?

Dec 31, 2015

$1.4 \times {10}^{8} \text{N}$

#### Explanation:

Using Pythagoras we can get the distance between the charges:

$d = \sqrt{{3}^{2} + {11}^{2}}$

$d = \sqrt{130} \text{m}$

From Coulomb's Law:

$F = \frac{k . {q}_{1} \times {q}_{2}}{r} ^ 2$

$\therefore F = 9 \times {10}^{9.} \frac{\left(2 \times - 1\right)}{130}$

$= \frac{18 \times {10}^{9}}{130} = 1.4 \times {10}^{8} \text{N}$