# Homework Help: Whats the magnitude of the velocity of the wind

1. Oct 19, 2005

### lisakells

A passenger on a ship traveling due east with a speed of 13.38m/s observes that the stream from the ship's funnels make an angle 20 (degrees) with the ships wake. The wind is blowing from south to north. Assume the smoke acquires a velocity(with respect to the earth) equal to the velocity of the wind as it leaves the funnels. Whats the magnitude of the velocity of the wind.

Last edited by a moderator: Sep 14, 2015
2. Oct 19, 2005

### Tom Mattson

Staff Emeritus
OK, so how did you start, and where did you get stuck?

You have to show your work here.

3. Oct 19, 2005

### lisakells

alright so the forumal X=distance after object accelerates for time
X0=initial distance
v=velocity after object accelerates for time
V0=initial velocity
a=acceleration
t=time
v=v0+at
x=x0+v0t+1/2at 2 squared
plunging it in is where iam stuck

4. Oct 19, 2005

### Tom Mattson

Staff Emeritus
You're just randomly grabbing equations, which won't do. First of all you've got to recognize that this is a two dimensional motion problem. And the second thing is that this is a relative motion problem.

Let $\vec{V}_{SE}$ be the velocity of the ship relative to the Earth.
Let $\vec{V}_{WE}$ be the velocity of the wind relative to the Earth.
Let $\vec{V}_{WS}$ by the velocity of the wind relative to the ship.

First question: How are these three quantities related?

5. Oct 19, 2005

### Tom Mattson

Staff Emeritus
Lisa: For the last time, stop posting your question all over the site.

You have to work with us. We are not going to do this problem for you.