Electric Field due to two points

Click For Summary
SUMMARY

The discussion focuses on calculating the net electric field at the origin due to two point charges: q_1 = -4.00 nC located at (0.60 m, 0.80 m) and q_2 = +6.00 nC at (0.60 m, 0). The correct approach involves using the formula E = (k * Q) / r² for each charge, summing their electric fields vectorially. The user initially miscalculated the electric field magnitudes and directions, leading to incorrect results. The correct method requires resolving the electric fields into their x and y components before summing them to find the resultant electric field.

PREREQUISITES
  • Understanding of Coulomb's Law and electric fields
  • Familiarity with vector addition and components
  • Knowledge of the constant k (Coulomb's constant) and its value (8.99 x 10^9 N m²/C²)
  • Basic algebra for manipulating equations and solving for unknowns
NEXT STEPS
  • Study vector addition of electric fields in electrostatics
  • Learn how to resolve vectors into components in two dimensions
  • Explore the implications of charge signs on electric field direction
  • Practice problems involving multiple point charges and net electric field calculations
USEFUL FOR

Students studying electrostatics, physics educators, and anyone seeking to understand electric field calculations involving multiple point charges.

Digdug12
Messages
15
Reaction score
0

Homework Statement


A point charge q_1 = -4.00 {\rm nC} is at the point x = 0.60 {\rm m}, y = 0.80 {\rm m} , and a second point charge q_2 = +6.00 {\rm nC} is at the point x = 0.60 {\rm m} , y = 0
Calculate the magnitude of the net electric field at the origin due to these two point charges.
Calculate the direction of the net electric field at the origin due to these two point charges.


Homework Equations


E=F/Q
F=k*q*q/r^2
E=(KQ1/r^2) + (KQ2/r^2)


The Attempt at a Solution


I searched the threads and I came up with one very similar to this problem, however i tried their solution and still comes out wrong. I am summing of the E fields produced by both charges, it looks like this

E=(8.99x10^9)(-4x10^-6)/1 + ((8.99x10^9)(6x10^-6)/.6^2
I get an answer around 113842 N/C, i tried different specific digits of K to get a more specific answer however they were all wrong, so i changed the sign of -4 to 4, just because, and i got 185793 N/C which is STILL wrong. I have no idea what I'm doing wrong?
and to solve for the angle, do i just use their vector components?
 
Physics news on Phys.org
Electric field is a vector quantity. You cannot add them directly. Find the direction of electric fields. One field due to 6.0 nC is along the -x-axis. Find the direction of the other field. Resolve it into x and y components and then find the net x and y components and find the resultant.
 

Similar threads

  • · Replies 10 ·
Replies
10
Views
4K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
23
Views
5K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
3
Views
1K
Replies
7
Views
2K
Replies
2
Views
3K