College Physics
posted by Kate .
How do I solve this problem:
A particular wire has a current of 10A.
A) How many electrons pass a fixed point every 5 seconds?
B)If a wire has a radius of 2 x 10^(3) m and the electron drift speed is 2.63 x 10^(5) m/s, determine the number density of electrons in the wire.
The teacher posts the answers for us, so the answer for
A) 3.125 x 10^(20) e^()
B) 1.89 x 10^(29) e^()/ m^3

It looks like you are switching names. Why?
A) Current (in Amperes) is charge passing by per second.
B) Current = (free electron number density)x (drift speed) x (cross sectional area)
Solve for the FREE electron density. (Electrons that remain attached to the nuclei of the conductor atoms are not included). 
Thanks for the help! And BTW, I am not switching my name.