please check my work on resultant vector

G

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The compass in a light aircraft shows that it is flying due north. The air speed indicator gives a reading of 150km/h. If there is a 50km/h wind blowing from west to east, what is the ground speed of the aircraft?

Answer:
The plane is moving 150km/h forward, it is also moving 50km/h right. If you draw out the vectors, as shown in the diagram below. Use pythagorean theorem.

c = sqrt(150^2 + 50^2)
c = sqrt(25000)
c = 158.11

Code: 
    50  
 _____________
|             /
|           /
|         /
|  150  / 
|     /
|   /
| / 
/

The above is the diagram. Please check my work; I am not sure it is correct.
 
You are SO close. The resultant vector is the one that is Due North. The heading of the aircraft must be somehwat to the West.
 
tkhunny is mistaken in this case ... you are correct.

The compass heading shows the direction the aircraft is traveling within the air mass ... the air mass itself is moving (wind) ... the resultant vector is the ground vector.
 
Every once in a while, I get my "course" and my "heading" confused. No worries. I am not a pilot or a navigator, commercial or otherwise, so you are not at risk. :shock:

This is the useful statement that I forgot to apply that will clear it up every time, "The compass reading is definitely showing the direction of the device to which it is attached -- the direction it is pointed."

Of course, we're not talking about a magnetic compass reading, only that whatever appropriate compass we have, understanding what it says, it says our "heading" is due north.

Well, I think I get it, now. I'm glad we had this discussion. :)
 
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