posted by john .
a very thin piece of copper wire has an electrical resistance of 20,000 Ohms. You connect its ends to a regular 2.0 Volt battery. How much power does it draw? Let's assume that this little piece of wire initially contained one trillion (that's a one with 12 zeros) mobile electrons which participate in the electric current flowing through it. How long does it take for an electron that was at one end of the wire when the battery was connected to travel to the other end?
P = V^2/R
Current I = V/R = 10^12* e /Time
(e is the electron charge)
Solve for time t.