Question about net electric field between two charges

[spencerchad]

Homework Statement

A charge +Q exists at a point and directly west of this point a charge -Q exists. What is the direction of the net electric field at the midway point?

I'm studying old finals for my exam and this question keeps popping up in various forms. The answer is always directed toward the negative charge. To me the answer should be zero if say Q=1.0C.

 

[Doc Al]

Ask yourself:
What's the direction of the field from the negative charge at the midpoint?
What's the direction of the field from the positive charge at the midpoint?

 

[ap123]

Draw a diagram and put in the directions of the electric fields of the 2 charges at the midway point.
Would these 2 fields add to zero?

 

[spencerchad]

Ah yes that make sense. I got hung up on "net" and thinking of the charges numerically rather than visualizing their electric field lines. Thanks for the quick reply!

 

[Nickie]

I can provide a response to this question by explaining the concept of electric field and how it is affected by the presence of two charges.

The electric field is a vector quantity that describes the strength and direction of the force experienced by a charged particle in the presence of other charges. It is defined as the force per unit charge and is represented by the symbol E.

In the scenario described, there are two charges present - a positive charge +Q and a negative charge -Q. According to the principle of superposition, the net electric field at any point is the vector sum of the individual electric fields due to each charge.

At the midway point between the two charges, the electric field due to the positive charge will be directed towards the negative charge, while the electric field due to the negative charge will be directed towards the positive charge. These two electric fields will cancel each other out, resulting in a net electric field of zero.

Therefore, the direction of the net electric field at the midway point will be zero, regardless of the magnitude of the charges involved.

It is important to note that this is a simplified scenario and in real-life situations, the electric field may not always be zero at the midway point between two charges. Factors such as the distance between the charges, the relative magnitude of the charges, and the presence of other charges or conductors can affect the net electric field at a given point.

In conclusion, while the answer to this question may seem counterintuitive, it is based on the fundamental principles of electric field and can be explained through the concept of vector addition.