Question

The starter motor of a car engine draws a current of 140A from the battery. The copper wire to the motor runs for 0.90s until the car engine starts. How much charge passes through the starter motor?

Answer 1

"1 Ampere" (A) means "1 coulomb of charge per second"

140 A means 140 coulombs per second

(140 coulomb/sec) x (0.9 sec) = 126 coulombs of charge.


Go a little farther:

Electrons are the things that move through wire carrying charge.

6.25 x 10¹⁸ electrons carry 1 coulomb of charge.

126 coulombs = 787,500,000,000,000,000,000 electrons (rounded)