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!

Relative velocity ship problem intuitively

  1. Sep 24, 2016 #1
    1. The problem statement, all variables and given/known data
    Two ships A and B are 4 km apart. A is due west of B. If A moves with uniform velocity of 8 km/hr due east and B moves with a uniform velocity of 6 km/hr due south. Calculate 1) the magnitudeof the velocity of A in relation to B 2) the closest distance apart of A and B

    2. Relevant equations
    The first solution is pretty simple but the second one, I dont get it. I know how to just solve it but without any intuition. Can someone help me get an intuitive idea of the solution of 2) ? The solution will be down there.

    3. The attempt at a solution
    In the example BD is drawn from B to relative velocity of A with respect to B represented by AE. From the given distance between A and B is 4km i.e. AB = 4km. In ABE sin x = BE/AE = 6/10 ( x= Angle EAB, BE = Velocity of B in opposite direction, AE = relative velocity of A in respect to B )
    x=36.67
    Closest distance apart from A to B is BD.
    Now in BDA,
    BD = sin x * AB = sin 36.87 * 4 = 2.4 km
    This is the closest distance.
     

    Attached Files:

  2. jcsd
  3. Sep 24, 2016 #2

    phinds

    User Avatar
    Gold Member
    2016 Award

    Posting tiny sideways pics is not a good way to get people to look at them.
     
  4. Sep 25, 2016 #3
    Dont have a good phone. Sorry. And vertical pictures are even tinier.
     
  5. Sep 25, 2016 #4

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    The idea is to use B's reference frame. In that frame, what are the NS and EW components of A's motion. At what point does B perceive A as being at closest approach?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Relative velocity ship problem intuitively
Loading...