Electrostatic force problems, help

AI Thread Summary
An isolated hollow metal sphere with a radius of 40 cm carries a charge of -10*10^-6. The electric field inside the sphere is indeed zero due to electrostatic shielding, confirming that there is no electric field within a hollow conductor. For the point 60 cm from the center, the distance should be measured from the center of the sphere, not the surface. The calculations provided by the user were based on incorrect assumptions, leading to errors in the results. Clarification on these concepts is crucial for understanding electrostatic forces and preparing for the upcoming test.
StudentPhys
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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 :(
 
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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?
 

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