How Does Side Length Influence Electric Flux Through a Cube?

[kirby2]

A point charge 6.50 nC is at the center of a cube with sides of length 0.260 m.

PART A: What is the electric flux through the surface of the cube?

PART B: What is the electric flux through one of the six faces of the cube?

ATTEMPT:

A)
Total flux enclosed by the cube = Q / eo
6.5E-9/8.85 x 10^-12= 734.5

B)
flux through one of the six faces is
= Q / 6 eo
so 734.5/6 = 122.4

with the exception of units, are these right? i think I'm doing it wrong because i didn't use the side length in any of the calculations.

 

[tiny-tim]

hi kirvy2!

… i think I'm doing it wrong because i didn't use the side length in any of the calculations.

no, your method is fine

 

[BruceW]

Agreed. It is one of the interesting things about the Coulombic force :) Maybe they were throwing you a red herring by giving you the length of the sides.