Answer:
E = 1053.365 J
Explanation:
∴ Q = 440μC * (  1 E-6 C / μC ) = 4.4 E-4 C
∴ C = k*εo*A / d
∴ k mica = 5.4
∴ εo = 8.8542 E-12 C² / N.m²
∴ A = 6.2cm * 6.2 cm = 38.44 cm² * ( m/100cm)² = 3.844 E-3 m²
∴ d = 2mm * ( m / 1000mm ) = 2 E-3 m
⇒ C = (( 5.4 ) * (8.8542 E-12 ) * ( 3.844 E-3 )) / 2 E-3
⇒ C = 9.1896 E-11 C²/N.m
⇒ E = ( 4.4 E-4 )² / (2*9.1896 E-11)
⇒ E = 1053.365 N.m = 1053.365 J