# A charge of 3 C is at (4 ,-7 ) and a charge of -1 C is at (-2 , 3 ) . If both coordinates are in meters, what is the force between the charges?

net displacement between the two charges is $r = \sqrt{{\left(4 - \left(- 2\right)\right)}^{2} + {\left(- 7 - 3\right)}^{2}} = \sqrt{136} m$
So, the electrostatic force acting between them will be $9 \cdot {10}^{9} \cdot 3 \cdot \frac{- 1}{136} = - 1.97 \cdot {10}^{8} N$ (using, $F = \frac{k {q}_{1} {q}_{2}}{r} ^ 2$)