# A charge of -2 C is at (4, -5) and a charge of 1 C is at (-3 , -9 ) . If both coordinates are in meters, what is the force between the charges?

Dec 28, 2017

$F \cong 0.27 \times {10}^{9} N$

#### Explanation:

Let A-=(4,-5) & B-=(-3,-9)
By distance formula,
AB=sqrt((y_2-y_1)^2+(x_2-x_1)^2

AB=sqrt((-9+5)^2+(-3-4)^2

$A B = \sqrt{16 + 49}$

$A B = \sqrt{65}$

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

$F = \frac{k \times 1 \times 2}{65}$

$F = \frac{9 \times {10}^{9} \times 1 \times 2}{65}$

$F \cong 0.27 \times {10}^{9} N$