# Finding the direction and velocity of wind using vectors question

1. Jun 6, 2013

### shy9488

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

A person, travelling eastward at a rate of 4.0 km/hr, observes that the wind seems to blow directly from the north; on doubling his speed the wind appears to come from the northeast; determine the direction of the wind and its velocity.

2. Relevant equations

3. The attempt at a solution

My teacher has actually given us the answers on this question. However, I am stuck at the point where she says the
Velocity of wind relative to person = Velocity of wind relative to the ground - velocity of person relative to the ground.

2. Jun 6, 2013

### tiny-tim

welcome to pf!

hi shy9488! welcome to pf!
it means that if you draw the three vectors (with arrows), then they join up to form a vector triangle

(and when the question says "observes that the wind seems to blow directly from the north", it means that the velocity of the wind relative to the person is north)

see the pf library, or wikipedia, for details