# Uniform line of charge and point charge

• noagname
In summary, the conversation discussed finding the x- and y-components of the electric field at a specific point due to an infinite line charge and a point charge. The solution involved using the equations for electric flux and electric field, and taking into account the direction and magnitude of the charges. Numerical results were obtained and checked using WolframAlpha. The final answers for the x- and y-components were -9545.026 kN/C and -4164.957 kN/C, respectively.

## Homework Statement

An infinite line charge of uniform linear charge density lambda = -3.1 mu or micro CC/m lies parallel to the y-axis at x = -1 m. A point charge of 0.7 mu or micro CC is located at x = 2.5 m, y = 3.5 m. Find the x- and y-components of the electric field at x = 3.5 m, y = 3.0 m.

flux = E*A = Q/ε
E = kQ/r^2

## The Attempt at a Solution

X axis:
To find the electric field from the line only: gaussian cylinder, centered on the line and r = 4.5m.
E*2∏*4.5*L = λL/ε -> E1 = λ/(ε*9*∏) to the left

From the point:
E2 = K(.7*10^-6)/1.25*sin(63.43°) to the right

Ex = E2-E1 Right?

Y axis:
The line don't matter because it cancels itself out. right?
Ey = K(.7*10^-6)/1.25*cos(63.43°) Down

Both answers need to be in kN/C, I'm at a loss, do you guys have any ideas? I have tried many different answers and I've checked all of the units.

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