Parallel-plate capacitor with two dielectric between them

[dakold]

Homework Statement

The upper and the lower conducting plates of a large parallel-plate capacitor are separated by a distance d and maintained at potentials V0 and 0, respectively. A dielectric slab bof dielectric constant 6.0 and uniform thickness 0.8d is placed over the lower plate. Assuming negligible fringing effect, determine the potential and eletric field distribution in the electric slab.

Homework Equations

nabla^2 V=-ρ/ε (1)
E=-grad(V) (2)

The Attempt at a Solution

I tried to solve the equ 1 but i don't know how to take in count that it's different dielectric constants between the two plates. I can solve the problem if the dielectric was the same between the plates but i can't know.

 

[Meir Achuz]

Treat it as two capacitors, one with vacuum, the other with the dielctric, in series.