Answer:
s = 4.425×10^-6 μm
Explanation:
C = Q/V
but also:
C = ∈×A/s
for A being the area of the plates, the :
Q = 30 nc/(cm^-2)
then:
Q = (30×10^-9)×A/V = ∈×A/s
∈ = 8.85 pF/m
that is: (30×10^-9)/V = (8.85×10^-12)/s
then, s = (8.85×10^-12)(150)/(30×10^-9)
= 4.425×10^-6 μm
Therefore, the spacing between the plates is 4.425×10^-6 μm.