Question: The starter motor of a car engine draws an electric current of 110 A from the battery. The copper wire to the motor is 4.20 mm in diameter and 1.73 m long. The starter motor runs for 0.95 s before the car engine starts up.
How much electric charge passes through the starter motor?
1.04Ã-102 C You are correct.
What is the current density in the wire?
How far does an electron travel along the wire while the starter motor is on? (The density of conduction electrons in copper is n = 8.50Ã-1028 1/m3.)