What is the average time between collisions for conduction electrons in copper?

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The discussion focuses on calculating the average time between collisions (T) for conduction electrons in copper using the formula T = (Vd)(Me)/(-e)(E). The user initially calculates the drift velocity (Vd) based on given current and dimensions of a copper wire, leading to a value of 9.4 x 10^-5 m/s. They encounter difficulty in determining the electric field (E) from the provided information, despite knowing the resistivity of copper. After some back-and-forth on the equations and variables, the user realizes they can derive the current density (J) to find E, ultimately leading to a solution. The discussion highlights the challenges of applying theoretical equations to practical problems in physics.
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Homework Statement


compute the average time between collisions T for conduction electrons in copper.


Homework Equations


Vd=-e*E*T/(Me)
Where e is electron's charge
E is electric Field
T is what I'm solving for
And Me is mass of the electron

Vd=I/PA


The Attempt at a Solution



so it was given that a copper wire with a 1.0mm diameter had a current of 1A...and it's mass density is 8900kg/m^3.
So m= 1 electron(8900kg/m^3)(6.02X10^23 atoms/0.0635kg) = 8.4 X 10^28/m^3
So
Vd=1A/(8.4X10^28 m^-3)(1.6X10^-19C)(7.9x10^-7m^2) = 9.4 x 10^-5 m/s

So now...
Vd=-e*E*T/(Me)

So T=(Vd)(Me)/(-e)(E)
I have Vd, Me is mass of the electron, and -e is charge of the electron. I need the electric force...and am stumped. How do I get it from the given info? Thanks for the help.
 
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Current density J = I/A, And resistivity of the material rho = E/J.
E = rho*I/A. For copper rho = 1.72x10^-8ohm.m
Vd = J/nq, where n is electron density in copper = 8.5x10^28 m^-3.
See whether these hints helpful to solve the problem.
 
Ok, so I get E=rho*J.....or since I don't know J J is also Vd*nq...so I get E=rho*Vd*nq...
so my equation becomes T=(Vd)(Me)/(-e)(rho)(Vd)(Nq)
stuff cancels and I get Me/(-e)(rho)(Nq) and I get a really wrong number. hmm
Edit. Nevermind...my bad. We Have I and A can be easily solved giving J. Thanks again, always appreciated.
 
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