Find the electric energy density. (Physics help!!!!)?

Question

An electric field is uniform. E= 3 i +2 j +1 k (x 10^3 N/C) find the electric energy density stored in this field.

Answer 1

Electric energy density is given by:

u = ½Ɛ₀E²

The magnitude of the electric field is:

E = (3² + 2² + 1²)^(1/2)

= 3.74 x 10^3 N/C

The electric energy density is:

u = 0.5 x (8.85 x 10^-12 F/m) x (3.74 x 10^3 N/C)²

= 6.19 x 10^-5 J/m^3