Results 1 to 5 of 5

Math Help - Bearings....

  1. #1
    Junior Member CONFUSED_ONE's Avatar
    Joined
    Jan 2006
    From
    Confused_One lives in the United States.
    Posts
    30

    Bearings....



    a ship leaves port with a bearing of S 40[degrees] W. after traveling 7 miles, the ship turns 90 degress and travels on a bearing of N 50[degree] W for 11 miles. At that time, what is the bearing of the ship from port?



    there's the picture that i drew for the diagram. sorry if it's confusing!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,830
    Thanks
    123
    Quote Originally Posted by CONFUSED_ONE
    a ship leaves port with a bearing of S 40[degrees] W. after traveling 7 miles, the ship turns 90 degress and travels on a bearing of N 50[degree] W for 11 miles. At that time, what is the bearing of the ship from port?
    Hello,

    you have to calculate an angle in a right triangle. Let be \alpha the angle at the point called port. Then you can use the tangens. And you'll get:
    \alpha=\arctan \left( \frac{11}{7} \right) \approx 57.5288^o \approx 57^o31'43.7''

    Now you have to caculate the bearing which is:
    180^o+40^o+57.5288^o=277.5288^o

    That means the bearing is now W 7.5288^o N. (A personal remark: When I worked as a seaman, we used numbers between 0^o (=N) \ to \ 360^o(=N) to name a bearing)

    Greetings

    EB
    Last edited by earboth; April 3rd 2006 at 09:38 PM. Reason: additional information
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member CONFUSED_ONE's Avatar
    Joined
    Jan 2006
    From
    Confused_One lives in the United States.
    Posts
    30
    Hello earboth,
    I thank you for solving this problem. In my calculations, the degree i got was 57 too. so that's good. what i don't understand is what you add to the degree to get the new bearing. why did you add 180 and 40 to it?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,830
    Thanks
    123
    Quote Originally Posted by CONFUSED_ONE
    Hello earboth,
    I thank you for solving this problem. In my calculations, the degree i got was 57 too. so that's good. what i don't understand is what you add to the degree to get the new bearing. why did you add 180 and 40 to it?
    Hello,

    as I've mentioned before I worked a s a seaman. The bearings we used are:

    0 or 360 = N
    90 = E
    180 = S
    270 = W

    Substitute the letters in your bearing (S 40 W) you get 180+40 because you go to W, that means your bearing is greater then 180.

    For me it's easier to calculate only with degrees instead of all the wests and easts and so on

    Greetings

    EB
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Junior Member CONFUSED_ONE's Avatar
    Joined
    Jan 2006
    From
    Confused_One lives in the United States.
    Posts
    30
    Ohh..i see now. THANK you again.
    Last edited by CONFUSED_ONE; April 4th 2006 at 10:25 PM. Reason: i mispelled!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. bearings
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: August 3rd 2008, 08:31 PM
  2. bearings
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: June 3rd 2008, 11:39 AM
  3. Bearings Help
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: March 22nd 2008, 07:54 AM
  4. bearings
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: October 17th 2007, 09:04 PM
  5. bearings
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: October 14th 2007, 01:49 PM

Search Tags


/mathhelpforum @mathhelpforum