Given that,
Electric field E = 5 V/m
The energy density formula is U = 1/2(╧╡ΓéÇE2)
= 1/2(8.8541 x 10-12 x 52)
= (4.42705 x 10-12 x 25)
= 110.67625 x 10-12
Therefore, the energy density of the capacitor is 110.67 x 10-12.