Multiplying by unit vector in electric field equation

AI Thread Summary
The discussion focuses on calculating the electric field and force on a proton due to two point charges. The user is tasked with finding the electric field at a specific point using the equation E = (kq/r²) x [r-hat], but is unclear about the unit vector r-hat and how to apply it in calculations. They suggest determining distances and angles between the points to resolve the electric fields into components. The approach involves calculating the distances from the charges to the point of interest and then using trigonometry to find the resultant electric field. Understanding the role of unit vectors is crucial for accurately determining the electric field's magnitude and direction.
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Homework Statement



A 5.0 μC point charge is located at x = 1.0 m, y = 3.0 m, and a −4.0 μC point charge is located
at x = 2.0 m, y = −2.0 m.

a) Find the magnitude and direction of the electric field at x = −3.0 m, y = 1.0 m. [5 Marks]
b) Find the magnitude and direction of the force on a proton at this position in a).

Homework Equations



E = (kq/r²) x [r-hat] (couldn't find the symbol for r circumflex)

The Attempt at a Solution



I can work out the first part of the equation, but I'm unsure what r-hat represents and what figure to use. I thought a unit vector was in the form Ai + Bj + Ck, how do you multiply that by a figure to get another single figure?
 
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Let point A be ( 1 m, 3 m) and point B be (2 m, -2 m). Let P be the point (-3 m, 1 m) where you want to find the electric field.
First of all find the distances AP and BP. Finding slope of the line AP and BP, you an find the angle made by the electric fields with x-axis. Then resolve them along vertical and horizontal components. Then find ΣEx and ΣEy and E.
 
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