Electron drift speed, Current, and Electric field in hollow wire?

[conov3]

Homework Statement

A hollow copper wire with an inner diameter of 1.4 mm and an outer diameter of 2.6 mm carries a current of 2.50 amps. Copper has an electron density of 8.5x1028 m-3 and a conductivity of 6.0x107 (ohm m)-1.
a. What is the electron drift speed in the wire?
b. What is the current density in the wire?
c. What is the electric field in the wire?

Homework Equations

a) I=n_eeV_dA
b)J=I/A
c)J=σE

The Attempt at a Solution

I believe I have the correct answers but was just curious if someone could double check me!
Thank you!

 

[telight]

Bra, your algebra is wrong. When you find the area, do it for each section separably and subtract them from each other you will see your error. X^2-Y^2 does not equal (X-Y)^2