Question

Two charges of `-1 C` and `-3 C` are positioned on a line at points `-2` and `12`, respectively. What is the net force on a charge of `4 C` at `-1`?

Answer 1

`vecF_(BD)=35.361*10^9 N`

Explanation:

Upon seeing the Diagram we first focus on the FBD for the charge at D .
general formula used here is
`F=1/(4piepsilon_o)*(q_1*q_2)/r^2`

`:.` `F_(DB)=9*10^9*(-1*4)/(1)^2=-36*10^9N`
Which is attractive force due negative x-axis direction .

`F_(DC)=9*10^9*(-3*4)/(13)^2=-0.639*10^9`
hence , `vecF_(DB)>vecF_(DC)`

so the direction is towards `vecF_(DB)`
hence the net force is in the direction of `vecF_(BD)=35.361*10^9 N`