Electrostatic force problems, help

Click For Summary
SUMMARY

The discussion centers on calculating the electric field of an isolated hollow metal sphere with a radius of 40 cm and a charge of -10 µC. It is established that the electric field inside a hollow conductor is zero, confirming that E = 0 N/C within the sphere. For points outside the sphere, the electric field can be calculated using Coulomb's law, specifically E = (9 x 10^9 N m²/C²)(-10 x 10^-6 C) / (d²), where d is the distance from the center of the sphere. The user incorrectly calculated the electric field at 60 cm from the center, leading to confusion regarding the application of distance in the formula.

PREREQUISITES
  • Understanding of Coulomb's Law
  • Knowledge of electric fields and their properties in conductors
  • Familiarity with the concept of charge and its units (Coulombs)
  • Basic algebra for manipulating equations
NEXT STEPS
  • Review the principles of electrostatics, focusing on electric fields in conductors
  • Study the application of Coulomb's Law in various scenarios
  • Learn about Gauss's Law and its implications for electric fields
  • Practice problems involving electric fields from point charges and spherical charge distributions
USEFUL FOR

Students preparing for physics exams, educators teaching electrostatics, and anyone seeking to understand electric fields in conductors.

StudentPhys
Messages
2
Reaction score
0
Electrostatic force problems, help urgent!

Homework Statement



Question: An isolated hollow metal sphere of radius 40 cm carries a charge of -10*10^-6.
What is the magnitude of the electric field E (a) in the empty space inside the sphere and (b) 60 cm from the center of the sphere ( no picture provided )

Homework Equations



Electrostatic force= K * q1*q2/ d^2


The Attempt at a Solution



I´ve tried to use Coloumb´s law to get to the correct answer , what I am having trouble to realize is 1. is there even an electric field within a hollow sphere,? and 2. do you count the distance in problem B from the surface of the sphere or from the center? I tried the center , and i got the wrong answer, don´t know if that is the problem. HELP URGENT , test coming up! :O :(
 
Physics news on Phys.org
Welcome to PF!

Hi StudentPhys! Welcome to PF! :wink:

Show us your full calculations, and then we'll see what went wrong, and we'll know how to help! :smile:
 


tiny-tim said:
Hi StudentPhys! Welcome to PF! :wink:

Show us your full calculations, and then we'll see what went wrong, and we'll know how to help! :smile:

My calculations are as follows:
I went on the assumption, having read it somewhere, that the electric field within a metallic sphere have 0 magnitude. and wrote E=0
and secondly 2) E= (9*10^9)(-10*10^-6)/ (0,6^2)= 32364 N/C

Though the key says these answers are incorrect , is this so or is the key wrong?
 

Similar threads

Why is the superposition principle valid here?
  • · Replies 5 ·
Replies
5
Views
1K
Electric field external to Conducting Hollow Sphere with charge inside
  • · Replies 23 ·
Replies
23
Views
5K
Use of imaginary charge vs Gauss' law
  • · Replies 12 ·
Replies
12
Views
1K
What is the net electrostatic force of the sphere at the origin?
  • · Replies 3 ·
Replies
3
Views
3K
Point charge with very thin metal sheet along a spherical surface
  • · Replies 21 ·
Replies
21
Views
2K
What does having 3d symmetry 2d symmetry and 1d symmetry mean?
  • · Replies 36 ·
2
Replies
36
Views
2K
Force on a part of a spherical shell on the other
  • · Replies 2 ·
Replies
2
Views
2K
Electrostatics: "Compressing" Charged Spherical Shell
  • · Replies 26 ·
Replies
26
Views
4K
Discontinuity in an Electric line of force
  • · Replies 12 ·
Replies
12
Views
3K
Electric field & force due to charged insulating hemispherical shells
  • · Replies 12 ·
Replies
12
Views
2K