Calculating drift velocity of electrons in a conductor

[michellewong]

Homework Statement

Calculate the drift velocity of the elctrons in a conductor that has a cross-sectional area of 8x10^-6m^2 and carries a current of 8A. Take the concentration of free electrons to be 5x10^28 electrons/m^3 with 1.6x10^-19C charge on each electron.

Homework Equations

The Attempt at a Solution

Have a problem like this one on my study guide. Wanted to see how it was done in steps.

 

[daviddeakin]

The amount of charge passing a point in the wire in time t:
Q = NqvtA

N = electron concentration
q = electron charge
v = drift velocity
t = time
A = cross-sectional area

So:
v = Q/(NqtA)

But current is:
i = Q/t
so substitute this in:

v = i/(NqA)