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!

Simple Vector Problem

  1. Sep 7, 2009 #1
    1. The problem statement, all variables and given/known data
    A child walks due east on the deck of a ship at 1 miles per hour.
    The ship is moving north at a speed of 4 miles per hour.

    Find the speed and direction of the child relative to the surface of the water.


    2. Relevant equations



    3. The attempt at a solution
    I've already found the magnitude. But now I can't find the direction.

    They want:

    "The angle of the direction from the north = "

    What does that mean? I've solved it using the inverse tangent for both angles of the triangle and apparently neither is right. So maybe it's even simpler than I think?
     
  2. jcsd
  3. Sep 7, 2009 #2

    Mark44

    Staff: Mentor

    What did you get for the angle relative to north? It should be somewhere between 10 and 20 degrees east of north.
     
  4. Sep 7, 2009 #3
    I got 14.03624347...in radians .2449786631(exact enough for you?:tongue2:)....does that sound about right?
     
  5. Sep 7, 2009 #4

    Mark44

    Staff: Mentor

    Your first value agrees with mine. I didn't calculate it in radians.
     
  6. Sep 7, 2009 #5
    Okay, cool. Thanks Mark, for all the help this morning(it's 2:30 here in Ohio). I can now begin my Materials and Energy Balances homework!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Simple Vector Problem
  1. Simple Vector Problem (Replies: 3)

Loading...