Electrostatic equilibrium problem

[Callumnc1]

Homework Statement:

Please see below.

Relevant Equations:

Please see below

For this problem,

I don't understand why this is impossible. Can someone please help?

Many thanks!

 

[kuruman]

What would be the magnitude of the electric field just outside the sphere?

 

[Callumnc1]

What would be the magnitude of the electric field just outside the sphere?

Thank you for your reply @kuruman ! The electric field of a sphere is equivalent to that of a point charge so $E = \frac {40 \times 10^{-9}k_e}{0.15^2}$

Many thanks!

 

[kuruman]

So why is the situation impossible?

 

[Callumnc1]

So why is the situation impossible?

Thanks for your reply @kuruman ! Thinking... Its got to me something to do with the electric field.

 

[kuruman]

Thanks for your reply @kuruman ! Thinking... Its got to me something to do with the electric field.

Yes. Look at the plot and then look at your post #3.

 

[Callumnc1]

Yes. Look at the plot and then look at your post #3.

Oh thanks @kuruman ! The calculated value for the electric field at the surface of the charge is not equal to that value on the graph.