# Two charges of  -5 C  and  -7 C are positioned on a line at points  5 and  4 , respectively. What is the net force on a charge of  -5 C at  0 ?

Jan 22, 2018

28.68×10^9 N along negative $X$ axis

#### Explanation:

Here, the $- 5 C$ charge at $x = 5$ tries to push the $- 5 C$ charge at $x = 0$

And the value of that force is $F 1$ = 9×10^9×(-5)×(-5)/(5^2) N or 9×10^9 N

The $- 7 C$ charge at $x = 4$ also tries to push it away due to repulsion in the same direction.

And,the value of that force is F2 = 9×10^9×(-7)×(-5)/(4^2) N i.e 19.68×10^9 N

So,total repulsive force towards negative $X$ axis is $F 1 + F 2$ i.e (9+19.68)×10^9 N or 28.68×10^9 N