# Trig - navigation problems.

#### clook

1. The problem statement, all variables and given/known data
A pilot wants to fly on a bearing of 68.2 degrees. By flying due east, he finds that 38 MPH, blowing from the south, puts him on the course. Find the air speed and ground speed.

2. Relevant equations
using law of sines/cosines, ambiguous case.

3. The attempt at a solution
Tried drawing a diagram according to the book, the one with grspeed/airspeed/wind direction/heading.

however, it seems like it's moving south and i would have to draw a different diagram to solve this.

i have NO idea where to start! this has stumped me. i'm not sure if i even have enough information to complete this problem. i just need a general idea of what kind of diagram i need to draw..

#### cristo

Staff Emeritus
Science Advisor
however, it seems like it's moving south and i would have to draw a different diagram to solve this.
The plane isnt moving south. The question states that, by flying due east, the wind (blowing from the south) ensures that the plane travels on the correct path of 68.2 degrees. How have you set up the diagram?

For the second part of the question, I don't know what the groundspeed means.

#### clook

http://savemyfile.net//files/6/book.jpg

something similar to this

Last edited by a moderator:

#### cristo

Staff Emeritus
Science Advisor
Ahh, ok I get what you mean now! Ok, well try drawing a diagram similar to that. The heading is the direction in which the pilot flies, ie due east here. The true course is the direction the pilot wants to fly, ie 68.2 degrees. The wind is blowing from the south. Your triangle will be different to the one in the book, in that it will be a right angled triangle.

#### clook

argh.. it would bea right triangle?

man, is there a way you could provide me some type of diagram for this?

edit: nvm, got it.

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