Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Colombs,Amps,Volts,and Watts. HELP

  1. Mar 9, 2007 #1
    Colombs,Amps,Volts,and Watts. HELP!!!!

    1. The problem statement, all variables and given/known data

    A given car battery is rated at 250 amp-hours. Does this rating indicate the amount of energy, power, charge, voltage, or current that can be drawn from the battery? Explain.

    2. Relevant equations

    Coulombs, Amps, Volts, Watts.

    3. The attempt at a solution

    I first calculated the coulombs that this battery produces in one hour. That turned out to be 250amp-hours X 3600seconds= 900,000.

    Is this the furthest that I can get?? I am really stumped because I thought I could get more than just the number of coulombs. I tried finding out how many electrons pass through (2.25x10^22) but it seems like I cannot learn joules or voltage by knowing how many total electrons a battery is capable of dispensing.

    I guess my problem is that I am equating the total number of electrons as a sort of total amount of energy. This is wrong?:cry:
  2. jcsd
  3. Mar 9, 2007 #2


    User Avatar
    Gold Member

    Your calculation has the right dimensions and is correct. But the 3600 is not seconds, it's just a number to convert the hours to seconds.

    Amp-hours is charge because amp=Coulomb/s.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook