Question
Find an example car (or other vehicle) battery, and compute how many of the AAA batteries in the previous problem it would take to equal the energy stored in it. Which is more compact?
Final Answer
It isn't clear which would be more compact.
Solution video
OpenStax College Physics for AP® Courses, Chapter 19, Problem 8 (Test Prep for AP® Courses)
vote with a rating of
votes with an average rating of
.
Prev
Calculator Screenshots
Video Transcript
This is College Physics Answers with Shaun Dychko. We are going to consider a car battery and figure out how many AAA batteries it would take to equal the same amount of energy. So the energy in a car battery is 60000 coulombs times 12.0 volts, which I have written as joules per coulomb to see that the coulomb's cancel and we are left with joules and that is 7.20 times 10 to the 5 joules and we get this information from example [19.1]. Okay! The amount of energy in a single AAA battery is 2000 coulombs times 1.5 volts, which is 3000 joules— and that comes from problem number 7 in the AP set. So the number of batteries—AAA batteries that is—it would take to have the total amount of energy equal to one car battery will be this amount of energy in a car battery times one AAA battery for every 3000 joules and this works out to 240 AAA batteries and it's not really clear, which would be more compact... 240 AAA batteries... these are pretty small versus one giant car battery.