Distance of Electrons with Electrostatic Force

Click For Summary

Homework Help Overview

The problem involves determining the distance required between two electrons on the Earth's surface for the electrostatic force between them to equal the weight of one electron. The subject area pertains to electrostatics and forces.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the relationship between the electrostatic force and the weight of an electron, with attempts to solve for the distance using the formula for electrostatic force. Questions arise regarding potential errors in calculations and assumptions about the influence of gravitational force.

Discussion Status

The discussion includes various attempts to calculate the distance, with some participants questioning the accuracy of previous calculations and the relevance of gravitational force in this context. There is no explicit consensus on the correct approach or solution yet.

Contextual Notes

Participants note the potential oversight of the gravitational force's impact compared to the electrostatic force, indicating a possible assumption that may need to be revisited.

kgal
Messages
41
Reaction score
0

Homework Statement


How far apart must two electrons be placed on the Earth's surface for there to be an electrostatic force between them equal to the weight of one of the electrons?


Homework Equations



Fe = (1 / 4∏ε0) X (q1q2 / r^2)


The Attempt at a Solution



I set Fe = me- (electrical force = mass of electron).

and solved for r = sqrt( q^2 / (me-)(4∏ε0) ) = 15.98 m, but the answer should be 5.08 m..
 
Physics news on Phys.org
hi kgal! :smile:
kgal said:
I set Fe = me- (electrical force = mass of electron).

and solved for r = sqrt( q^2 / (me-)(4∏ε0) ) = 15.98 m, but the answer should be 5.08 m..

hmm … 15.98/5.08 = π …

did you lose a π somewhere?​
 
The WEIGHT of an electron = me x 9.81, I got the answer to be 5.02m
 
i attached the picture.

I don't see the flaw...
 

Attachments

  • photo.jpg
    photo.jpg
    21.3 KB · Views: 1,093
thanks technician!

i thought that i have to ignore g because its so small compared to the electrical forces...
 

Similar threads

Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 9 ·
Replies
9
Views
985
  • · Replies 8 ·
Replies
8
Views
2K
Replies
7
Views
10K
  • · Replies 22 ·
Replies
22
Views
4K
  • · Replies 3 ·
Replies
3
Views
1K
Replies
1
Views
2K
Replies
21
Views
2K
  • · Replies 19 ·
Replies
19
Views
2K