Homework Help: Gauss's Law - point charge and charged sphere.

1. The problem statement, all variables and given/known data

A point charge q1 = -9.7 μC is located at the center of a thick conducting shell of inner radius a = 2.3 cm and outer radius b = 4.5 cm, The conducting shell has a net charge of q2 = 1.4 μC.


1) What is Ex(P), the value of the x-component of the electric field at point P, located a distance 8.2 cm along the x-axis from q1?



2. Relevant equations

E=K*q/r^2



3. The attempt at a solution

I'm honestly not sure where to start. I tried computing Eq1 at the inner edge of q2, then determining the resulting E at the outer edge of q2 then using that q value and computing E from the outer edge to P. Needless to say I didn't get the right answer.

Also, I'm new here...Last year (phys 1) I got by well enough to get a B+ in the class, but once we got beyond statics and dynamics and rotional forces (i.e. once we got to electrical/magnetic and hydrostatic forces) I was kind of lost. This year (phys 2) I'm planning to stay on top of things and actually UNDERSTAND the material, not just get a passing grade. Hence the reason I joined this forum - I apologize in advance for any dumb questions - if you see it on here rest assured that I spent at least an hour trying to figure it out on my own.

Any help is greatly appreciated!

 

Can you explain that in terms of the equations?