# Relative velocity problem. NEED HELP.

## Homework Statement

A jet airliner moving initially at 300 mph due east enters a region where the wind is blowing at 100 miph in a direction 30° north of east. What is the new velocity of the aircraft relative to the ground?

## Homework Equations

I don't know any equations for this question.

## The Attempt at a Solution

I thought it might be like using the 300 mph... caculate the hypotenus velocity vector using the angle, and add 100 mph... I don't think it's right.

Last edited:

Astronuc
Staff Emeritus
This is a vector addition problem. One adds the planes velocity vector to the winds velocity vector. The plane is supported/carried by the wind and the wind is moving, which is much like a boat in a river with a current.

So pick a coordinate system, and the determine the components of each vector.

Pick the direction to East as +x, and the direction to North as +y.

Oh wait... so if the plane's velocity vector was A, and the wind's velocity vector was B.
It would be B + A = R?
R being the new velocity vector relative to the ground.

Last edited:
Astronuc
Staff Emeritus