# Two charges of  -1 C  and  2 C are positioned on a line at points  -2  and  2 , respectively. What is the net force on a charge of  2 C at  1 ?

Feb 9, 2017

${F}_{21} = 2.25 \ast {10}^{9}$
$F = k {q}_{1} \ast {q}_{2} / {r}^{2}$
So we can put ${q}_{1} = 2 \mathmr{and} {q}_{2} = 1$
As sign is never considered and r = 4 from -2 to +2..and $k = 9 \ast {10}^{9}$
You will get $2.25 \ast {10}^{9}$ as answer