How to Calculate the Electric Field Near a Long Charged Wire?

AI Thread Summary
To calculate the electric field near a long charged wire, the discussion emphasizes using Gauss's law when the wire's length is significantly greater than the distance from the point of interest. The relevant equations include E = kq/r^2 and E = kQx/(x^2 + a^2)^(3/2). Initial attempts to solve the problem involved treating the wire as a circle, which was unsuccessful. Ultimately, the user resolved the issue independently. The conversation highlights the importance of selecting the appropriate method for calculating electric fields in different scenarios.
K3nt70
Messages
82
Reaction score
0

Homework Statement


Calculate the electric field at a point 2.00 cm perpendicular to the midpoint of a 1.94 m long thin wire carrying a total charge of 4.78 uC.

Hint: You could integrate BUT if the wire is very long compared to the distance from the wire to where you are calculating the electric field, then the electric field will be radial and Gauss's law might be easier.

Homework Equations



E = \frac{kq}{r^2}

where k = 9E9
q = 4.78E-6
r = 0.02 m

E = \frac{kQx}{(x^2 + a^2)^(3/2)}


The Attempt at a Solution



First i tried to use the second formula where i made the wire into a circle and used 0.02m as the radius. That didnt work, so i used gauss's formula as the hint suggests, which also didnt work. Suggestions?
 
Physics news on Phys.org
Nevermind, i solved it.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Trying to understand the logic behind adding vectors with an angle between them'
My initial calculation was to subtract V1 from V2 to show that from the perspective of the second aircraft the first one is -300km/h. So i checked with ChatGPT and it said I cant just subtract them because I have an angle between them. So I dont understand the reasoning of it. Like why should a velocity be dependent on an angle? I was thinking about how it would look like if the planes where parallel to each other, and then how it look like if one is turning away and I dont see it. Since...
Back
Top