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!

Minimize Distance

  1. Jan 17, 2007 #1
    1. The problem statement, all variables and given/known data
    Mike, who i standing on the deck of a yacth that is travelling due west at 6km/h, sees a sailboat sailing southwestat 4km/h, 3km northwest of the yacht. How close to each other do these boats get?


    2. Relevant equations



    3. The attempt at a solution
    My drawing is:
    | A(2.12-4t,2.12-4t)
    | / \
    | / \
    |/__\B(4.24-6t,0)

    Used pythagorean theorem to find t [tex]D^2=(2.12-4t-0)^2+(2.12-4t-(4.24-6t))^2[/tex]

    Correct so far?
     
    Last edited: Jan 17, 2007
  2. jcsd
  3. Jan 18, 2007 #2

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    You have sailboat A with a velocity of <-4, -4>. That gives a speed of
    [itex]\sqrt{16+ 16}= 4\sqrt{2}[/itex], not 4. You need to multiply by
    [itex]\frac{\sqrt{2}}{2}[/itex], just like you did with the initial position.

    And it would be a good idea to specifically state, in your final answer, which sailboat is A and which B and how your coordinate system is set up.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?