Electric Potential Car Battery Problem

[maphco]

Homework Statement

A particular 12V car battery can send a total charge of 84 A-h (ampere-hours) through a circuit, from one terminal to the other. (a) How many coulombs of charge does this represent? (b) If this entire charge undergoes a change in electric potential of 12V, how much energy is involved?

Homework Equations

The Attempt at a Solution

I'd just like some advice in starting the question, simply because I'm not accustomed to working in Ampere-hours. Just a hint would do nicely.

 

[rootX]

Ampere-hours = 1A*1h
so, they multiplied their current by the time
and now just use simple formulas ..
i = change in q/change in time ..

 

[maphco]

I'm still not sure how thew book gets an answer of 3.0 x 10^5 C

 

[maphco]

Anyone got any other hints?

 

[Dick]

I think an amp is 1 coulomb per second. What do you think it is? That's a hint, son.

 

[maphco]

So for an hour the charge would be 84 * 60?

 

[Dick]

It would be if an hour were equal to 60 seconds. But it isn't.

 

[maphco]

Ohhhhhhhhhhhh, alright, I get it. It's a simple dimensional analysis problem. Yeesh, why didn't I realize that...