Two identical charges, both 30 μμc, are located on the y-axis at y=5 cm and y=-5 cm. What is the magnitude of the electric field on the x-axis at x=12 cm? round your answer to 3 significant digits.

Respuesta :

We will see that the electric field in that point is:

Ex = 31.598 N/μc

How to find the electric field?

Remember that for a charge Q, the electric field is given by:

[tex]E = k*\frac{Q}{r^2} (n_x, n_y)[/tex]

Where the versor is in the direction of r,  k is a constant, and r is the distance to the charge.

In this case, we have two charges, one at  (0cm, 5cm) and the other at (0cm, -5cm). Because of the symmetry on the y-axis, we know that the y-component will be canceled, so we only have the x-component.

[tex]E_x = k*(\frac{30 \mu C}{(12cm)^2 + (5cm)^2} + \frac{30 \mu C}{(12cm)^2 + (-5cm)^2} )\\\\E_x = k*(\frac{60 \mu C}{169cm^2})[/tex]

Now we know that the value of k, the Coulomb's constant is:

k = 8,9*10^9 N*m^2/C^2

Writing this in cm and μc (multiplying by 10^4 and dividing by 10^12 we get)

k = 8.9*10^9*(10^4*10^-12) N*cm^2/μc^2

k =  8.9*10 N*cm^2/μc^2

Now we use that in our equation:

[tex]E_x = (8.9*10 N*cm^2/\mu c^2)*(\frac{60 \mu C}{169cm^2}) = 31.598N/\mu c[/tex]

This is the electric field on the point (12cm, 0cm).

If you want to learn more about electric fields, you can read:

https://brainly.com/question/1592046