The difference of voltage between the two plates of the capacitor is equal to the electric field intensity E times the distance between the plates:
[tex]\Delta V = E d[/tex]
so, from this we find d, the distance between the two plates of the capacitor:
[tex]d= \frac{\Delta V}{E}= \frac{35.0 V}{750 V/m}=0.047 m [/tex]
And since we know also the area of the plates, we can find the capacitance:
[tex]C=\epsilon _0 \frac{A}{d}=(8.85 \cdot 10^{-12}F/m) \frac{4.0 \cdot 10^{-2}m^2}{0.047 m}=7.53 \cdot 10^{-12} F [/tex]
