Helicopter Direction in Vector: Solving w/ Tan-1

[chukie]

A helicopter is flying southeast with a speed of 200 m/s and the wind is blowing northeast with a speed of 60 m/s.

Which direction will the helicopter head now?
I know that u use tangent to solve for the angle. except I am unsure whether it should be tan-1(200/60) or tan-1(60/600) and is the direction southeast?

http://img50.imageshack.us/img50/5665/vectordk0.th.jpg

 

[Kurdt]

\tan \theta = \frac{o}{a}

where o = opposite side and a = adjacent side.

 

[chukie]

\tan \theta = \frac{o}{a}

where o = opposite side and a = adjacent side.

yes i know except i don't know which angle to solve for. the one between the wind and the resultant or between the helicopter and the resultant?

 

[Kurdt]

It depends where the 0 angle is set. I would presume everything will be measured clockwise from North. If the question is not specific then you could just state where you've measured the angle from.

 

[chukie]

It depends where the 0 angle is set. I would presume everything will be measured clockwise from North. If the question is not specific then you could just state where you've measured the angle from.

i don't quite understand. do you mean that it doesn't matter which angle i find?

 

[Kurdt]

Which one will be the angle that will allow you to work out the angle from North?

 

[HallsofIvy]

To give the "direction" the helicopter will go you need to find the angle between NORTH and the vector representing the true path of the helicopter. Which angle in you diagram will give you that? What do the three vectors in your diagram represent and which shows the true path of the helicopter?

 

[chukie]

oh okay thanks! i understand now!