Vectors

[a.a]

1. The problem statement, all variables and given/known data

1 A light plane is travelling at 175km/h on a heading of 8° east of north in a 40-km/h wind from 80° east of north. Determine the plane's ground velocity.

2. Relevant equations

cosine law


3. The attempt at a solution
I found the resultant to be 191 km/h but the answer is 167 km/h

[_Mayday_]

Show us your working a.a it will help us see where you have gone wrong if you have. :smile:

[tiny-tim]

I found the resultant to be 191 km/h but the answer is 167 km/h

Hi a.a! :smile:

You've added the 2*40*175*cos72 instead of subtracting it.

I expect you've drawn the triangle wrong.

If the velocity of the plane the air and the ground are P A and G, then the question asks for P - G, which is (P - A) + (A - G).

Draw the triangle so that the arrows go the right way. :smile: