# Sketch the Electric Field at point "A" due to the two point charges

• jbyolo101
In summary, the conversation was about a problem involving Coulomb's law, Superposition Principle, 2D vector algebra, and geometry. The person asking the question was struggling with finding the direction and magnitude of the electric field at point A due to point B and point C. They were advised to use trigonometry and to carefully consider Coulomb's Law in finding the resultant of the two arrows representing the electric fields. The person admitted they may have drawn the arrows incorrectly and needed guidance on adding them to get the resultant.

#### jbyolo101

New user has been reminded to show their work on schoolwork problems
Homework Statement
Have attached image with the questions, this is so confusing for me.
Relevant Equations
?

Do you understand the question? Per forum rules, you need to show some attempt, or at the least describe what is stopping you.
Can you at least say what direction the field at point A will be from the charge at point B?
For relevant equations, you must have been taught an equation for the magnitude of the field at distance r from charge q.

Delta2
Tell us at least that you know Coulomb's Law for electrostatics, otherwise I don't think we can help you.

This problem involves Coulomb's law, Superposition Principle, 2D vector algebra and some geometry.
For which of the above 4 sub sections you think you have a problem with?

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Start by drawing an arrow to represent the electric field at A due to B only. Direction is important but magnitude not yet.
Once you've done that, draw an arrow to represent the electric field at A due to C only. How will it differ from the field due to B in direction? How will its magnitude compare to that due to B? (be careful, think of Coulomb's Law and about how field strength varies with distance).
Now you just have to find the resultant of your two arrows.

I think I’ve done it wrong :/

check trigonometry.

2milehi
jbyolo101 said:
View attachment 285345
I think I’ve done it wrong :/
It's not entirely wrong so far. You could have drawn the arrows more to scale. Which one should be longer than the other and by what factor? Do you know how to add the two arrows to get the resultant? Please note: Angle BAC is not 30o as you show in the drawing.

2milehi