1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Understanding formulas involving divison and multiplication

  1. Jun 1, 2014 #1
    I've never quite understood is how formula can involve division and multiplication while dealing with abstract concepts. Such as, ohm's law V = I•R where V=voltage applied I=current and R=resistance. How does that work exactly? how can you multiply two abstract concepts together to understand the equivalence to something else. Is this to assume we are evaluating for something, correct? if we know the certain number of volts and the current we can figure out the voltage? if this is correct can this be reversed in order to figure out the others alone, such as I and R?

    Other formulas such as Speed = distance / time. Things like these have always confused me, maybe I just don't quite understand division but how can diving possible given you the outcome of speed?
    Also anything dealing with infinities and pi in formulas I don't see how these are work together to form an understanding.

    Please help
  2. jcsd
  3. Jun 1, 2014 #2


    User Avatar
    Homework Helper

    Many times it is a definition. Like (speed = distance / time), that's just the definition of speed. Mathematics is just a language and that is the mathematical translation of "speed is distance per time" or "speed is how long it takes to go a distance" or "speed is how far you go in an amount of time"
    Those are 3 verbal (english) ways of defining speed. Division is just part of the language used in the mathematical definition.

    As with any language, you have to use it quite a bit before you can understand it fluently. You have to use it a lot to understand the subtle meanings involved, and you also have to use it a lot before you can think with it.
  4. Jun 1, 2014 #3


    User Avatar
    Science Advisor

    How would you calculate speed instead?
  5. Jun 1, 2014 #4


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    Speed is a 'concept'. You can't avoid the Maths.
  6. Jun 1, 2014 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    What about ratios? How do you feel about them?

    Your post implies that you accept addition and subtraction w.r.t. abstract concepts. Why?

    If you wanted to calculate the area of a square or rectangle, how would you do it?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Understanding formulas involving divison and multiplication
  1. Multiple batteries (Replies: 2)