At what position is the net electric field equal to zero?

[laxwarrior]

Two charges are separated by 1.0 m. Q1 has a negative charge of 4.2 µC and Q2 has a positive charge of 1.4 µC. At what position is the net electric field that is produced by both Q1 and Q2 equal to zero?

Extra Credit: If a +5.0 µC charge is placed at this position, what force would act on it as a result of Q1 and Q2?

 

[Stonebridge]

You need to show your attempt at this question before we can help.

 

[kerimek]

The net electric field will be equal to zero at a position equidistant from both Q1 and Q2. This position can be found by using the equation E = kQ/r^2, where E is the electric field, k is the Coulomb's constant, Q is the charge, and r is the distance between the charges. In this case, the charges are separated by 1.0 m, so the net electric field will be equal to zero at a distance of 0.5 m from each charge.

If a +5.0 µC charge is placed at this position, it will experience a force due to both Q1 and Q2. The force can be calculated using the equation F = kQ1Q2/r^2. Plugging in the values for Q1, Q2, and r, we get a force of 1.4 x 10^-4 N, directed towards Q1. This shows that the force on the +5.0 µC charge is repulsive, as expected since Q1 and Q2 have opposite charges. The direction and magnitude of the force can also be determined by using the principles of vector addition.