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!

Question about total vector displacement, BUGGING ME OUT

  1. Mar 29, 2008 #1
    If I were to drive south at 20.0 m/s for 3 min, then turn west and travel at 25 m/s for 2 min, and finally travel northwest at 30.0 m/s for 1.00 min. what would my total vector displacement be?

    I start out by converting minutes to seconds, so I have position vectors; 1800m to south, 3600m west, and 1800m NorthWest. Then using the respective vector units, I add them up, and square each component, and take the square root. I keep getting a different answer, please help.

    Displacement Vector = Sqrt ( (3600 +1800cos45 + 0)i ^2 + ((1800sin45 +3000)^2 j))

    Am i on the wrong track here, this is REALLY bugging me out!!!
  2. jcsd
  3. Mar 29, 2008 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Welcome to PF,
    You need to sort your unit vectors out. Here you have north & south and east & west as the same direction.

    Usually, i would be directed from west to east and j would be directed from south to north.
  4. Mar 29, 2008 #3
    How would I go about finding the average speed? I figured out that average speed is the magnitude of the average velocity vector = Delta (R)/Delta(T), so How does that apply to this problem?
  5. Mar 29, 2008 #4
    bummp, anyone?
  6. Mar 30, 2008 #5
    Average speed is total distance/time. Not always the same as average velocity.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Question about total vector displacement, BUGGING ME OUT