# Homework Help: Velocity x component

1. Sep 17, 2011

### tryton

1. The problem statement, all variables and given/known data
A jetliner is moving at a speed of 233 m/s. The vertical component of the plane's velocity is 66.9 m/s. Determine the magnitude of the horizontal component of the plane's velocity.

3. The attempt at a solution
233m/s^2=66m/s^2+x^2=233.189135m/s
66m/s cos(90)=0

I am not really sure how to find velocity from speed without knowing the angle... It's not given that it is 90... I know this is supposed to be easy but I am a beginner.

Thanks for help

2. Sep 17, 2011

### USN2ENG

You are almost there:
So its Vx=Vcos(theta)

So then with algebra its: arccosine(Vx/V)=theta....plug in your given numbers..
Theta = 73.3 degrees

Then find the y component with Vy=Vsin(73.3) = 233sin(73.3)=223 so Vy=223m/s

to check this then you would do sqrt(Vx^2+Vy^2)=V

Last edited: Sep 17, 2011
3. Sep 17, 2011

### SaltyBriefs

Beat me to it. But yeah do this.

4. Sep 23, 2011

### tryton

Thanks!!! That was helpful!

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