# Homework Help: Resultant vector

1. Sep 20, 2007

### brittbratt117

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

**calculate the resultant velocity of an airplane that normally flies at 200km/h if it encounters a 50km/h tailwind. IF it encounters a 50km/h headwind.

its obvious that each would either slow down the plane or speed it up but i dont know how

Last edited: Sep 20, 2007
2. Sep 20, 2007

### Staff: Mentor

Just remember that there are two speeds for a plane -- the airspeed and the groundspeed. The groundspeed would be dependent on the airspeed (the speed the plane sees itself going through the air) and the speed of any wind.

3. Sep 20, 2007

### Astronuc

Staff Emeritus
The tail wind is flowing in the direction of the plane, and the head wind comes directly at the plane, i.e. the wind flows in the opposite direction of the plane's velocity.

Simple addition would require simply adding the corresponding components of each vector. The coordinate system is important therefore.

See this for reference on basic vector operations:
http://hyperphysics.phy-astr.gsu.edu/hbase/vect.html