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!

Homework Help: The Difference Between Equation Uniform Acceleration and Average elocity

  1. Aug 27, 2012 #1
    1. The problem statement, all variables and given/known data

    I was just wondering in what instances you would use the two equation belows, and what the difference is between them.

    2. Relevant equations

    average velocity:

    vave = Δx/Δt

    Uniform Acceleration:

    vave = (vi+ vf )/2

    3. The attempt at a solution
    I'm assuming that the second equation is just a way of finding the average velocity of time and distance are not known.
  2. jcsd
  3. Aug 27, 2012 #2
  4. Aug 27, 2012 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    The first equation, [itex]\displaystyle v_\text{ave}=\frac{\Delta x}{\Delta t}[/itex] is a definition for average velocity, so it's always true.

    The second equation, [itex]\displaystyle v_\text{ave}=\frac{v_\text{initial}+v_\text{final}}{2}[/itex] is true for the case of uniform (constant) acceleration. It's not true in general, if the acceleration is not constant.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook