Electric fields of a hallow ball

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Kibbel
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Homework Statement



A hollow ball of radius 5 cm, made of very thin glass, is rubbed all over with a silk cloth and acquires a negative charge of -9.5e-08 C which is uniformly distributed all over its surface. Location A, shown in the diagram, is inside the sphere, 1 cm from the surface. Location B, shown in the diagram, is outside the sphere, 2 cm from the surface. There are no other charged objects nearby.
Which of the following statements about Eball, the magnitude of the electric field due to the ball, are correct? Select all that apply.

1. At location A Eball is 0 N/C.
2. At location B Eball is 2.14 x10^6 N/C.
3.A hydrogen atom at location A would polarize because it is close to the negative charges on the surface of the sphere.
4.All of the charges on the surface of the sphere contribute to Eball at location A.


Homework Equations


(1/4*pi*epsilon)*Q/R^2


The Attempt at a Solution


So i checked at point B that the it is ~2.14 x10^6 N/C. I thought that inside the sphere the electric field is 0, but its an insulator so that means its not. And I am guessing that all of the charges contribute to Eball at location A?

is that looking correct?
 
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Ill go through my thoughts again for each answer:

1. I do not believe that at point A the E of the ball is 0. (Location A is inside the sphere) This is because in an insulator even though the charge on the outside is uniformly distributed, the A is not in the center.

2. That is correct, the location at B is 2.14, according to the numbers given uptop

3.I believe if you placed a hydrogen atom at location A it would polarize because on an insulator there are not free ions to move around so the electron cloud on the atom would move, polarizing it.

4. Yes I do believe that all of the charges on the surface of the sphere act on the location A inside the sphere. And this is why it is cause to not have a field of 0

so, No, Yes, Yes, no, does anyone know if I'm correct, or at least on the right track?
 
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