1. Not finding help here? Sign up for a free 30min 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!

Finding average speed given two velocities, help!

  1. Oct 9, 2008 #1
    1. The problem statement, all variables and given/known data
    A person walks first at a constant speed of 47.0m/s along a straight line from point A to point B and then back along the line from B to A at a constant speed of 3.10m/s


    2. Relevant equations
    What is her average speed over the entire trip?


    3. The attempt at a solution
    I tried (4.70m/s + 3.10m/s)/2 to get the average and got 3.9m/s but it was wrong...I can't really think of anything else b/c time isn't given...
     
  2. jcsd
  3. Oct 9, 2008 #2

    LowlyPion

    User Avatar
    Homework Helper

    The average speed is the distance traveled divided by time.
    Your answer is for equal time intervals at different speeds.
    But you have unequal time intervals.
    You need to find the total time that it took to go twice the AB distance.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?