Question

Two charges of `-2 C` and `3 C` are positioned on a line at points `3` and `4`, respectively. What is the net force on a charge of `-3 C` at `0`?

Answer 1

`9.3*10^8 N`

Explanation:

Two charges of `−2C` and `3C` are positioned on a line at points
3 and 4, respectively.

To find the net force on a charge of -3C at 0.

Force on -3C at 0 due to -2C placed at 3.
`F_1=(kq_1q_2)/r^2=(k(-2)(-3))/3^2=(2k)/3`

Force on -3C at 0 due to 3C placed at 4.
`F_2=(kq_1q_2)/r^2=(k(3)(-3))/4^2=(-9k)/16`
Total Force
`F=F_1+F_2=(2k)/3-(9k)/16=(32-27)/48k=5/48k`
`F=5/48*9*10^9=45/48*10^9N=9.3*10^8 N`