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!

Electric Circuits Homework Help

  1. Jan 19, 2010 #1
    I dont have much of a homework problem that i need help with, but the homework requires us to use a equation ...

    P = E / t

    there is a little triangle before the E
    i don't know what it means

    Thanks for help
    Last edited: Jan 19, 2010
  2. jcsd
  3. Jan 20, 2010 #2
    [tex]P=\frac{\Delta E}{t}[/tex]
    I can tell you what the [tex]\Delta[/tex] (capital delta) and the t mean but I can't be sure what the equation is all about unless I know that E or P is.
    [tex]\Delta[/tex] means "change in." As in change in the variable between two points, generally time or space. In this case between two points in time as you have a per t.
    I have seen P mean momentum, power, point, polarization, and dipole moment. I have seen E mean energy and electric field. Only two of these makes sense together in this equation.
    I think P is power measured in watts, E is energy measured in joules, and t is time measured in seconds. It would read "Power is equal to the change in energy per unit time." For this version to work, you need to know the objects energy at two points in time, find their difference, and then divide by the time between the two points in time.
    I will see this equation as either:
    [tex]P=\frac{\Delta E}{\Delta t}=\frac{dE}{dt}[/tex]
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Electric Circuits Homework Date
How to calculate the equivalent resistance using wye delta ? Jan 2, 2016
Physics Olympiad question Electric circuit Nov 11, 2015
Easy Capacitor question May 7, 2015
Electric Circuits Homework Help Jan 20, 2010