Ask Experts Questions for FREE Help !
Ask
    hjacks6's Avatar
    hjacks6 Posts: 4, Reputation: 1
    New Member
    		  
    #1

    Nov 19, 2010, 11:47 PM
    Mathematics Trigonometry & Bearings Question
    Two cyclists depart from the same point. One travels due East at 18km/hr while the other travels North-West at 20km/hr. How long (to the nearest minute) will it be before they are 80km apart?
    Unknown008's Avatar
    Unknown008 Posts: 8,076, Reputation: 723
    Uber Member
    		  
    #2

    Nov 20, 2010, 12:56 AM

    Do you know the cosine rule?

    If you have a triangle ABC with opposite angles opposite to side A labelled a, B labelled b and C labelled c, you get:



    Here, A = 80
    B = 18t
    C = 20t
    a = (90 + 45) = 135 degrees

    where t is the time you are looking for.
    hjacks6's Avatar
    hjacks6 Posts: 4, Reputation: 1
    New Member
    		  
    #3

    Nov 26, 2010, 10:42 PM
    Comment on Unknown008's post
    Hi Thank you so much... I didn't think about Northwest as 45 degrees... and that's why was wondering what could the angle. But thanks a lot. I got the answer now.
    Unknown008's Avatar
    Unknown008 Posts: 8,076, Reputation: 723
    Uber Member
    		  
    #4

    Nov 27, 2010, 12:20 AM

    You're welcome :)
Not your question? Ask your question View similar questions
 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Trigonometry and Bearings [ 5 Answers ]

An aeroplane flies 120km on a bearing of 130 degrees. It then alters course and flies 250km on a bearing of 035 degrees. a) How far east is the plane from its starting point? b) How far north is the plane from its starting point? c) How far is the plane from its starting point? :confused:

Trigonometry - Bearings? [ 5 Answers ]

Please answer the question with diagram. An aircraft flies 400km from a point O on a bearing of 25 degrees and then 700 km on a bearing of 80 degrees to arrive at B. How far north of O is B? How far east of O is B? Find the distance and bearing of B from O?

Trigonometry bearings [ 6 Answers ]

A ship sailed from Port K to Port L. Port L is located 28km East and 16km South of Port K. Calculate the distance of KL and the bearing of Port L from Port K. Give answer correct to 3 significant figures.

Trigonometry (bearings) [ 4 Answers ]

A boat sails form port on a bearing of 290 degrees for 130 nm. How far north is it form its starting point?

View more questions Search