(adsbygoogle = window.adsbygoogle || []).push({}); Dynamics Help Needed!! Relative velocities problem

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

see link:

http://www.flickr.com/photos/55153239@N03/6199846646/

2. Relevant equations

Can you please help me solve this problem?

I have 3 unknowns: Va, Vb, and Thetha; but only two equations

Vb(cos(theta)) - Va(cos30) = 5.6cos70

Vb(sin(theta)) - Va(sin30) = 5.6sin70

I need a third equation???!?!

3. The attempt at a solution

To get the two above equations, I took into account:

Vb/a = Vb - Va

Then I broke each vector into components. I end up with the two above equations. But I don't know where to go from here. I need a third equation either relating theta to Va or Vb, or a cable constraint equation, etc. I need some help.

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# Homework Help: Dynamics Help Needed Relative velocities problem

**Physics Forums | Science Articles, Homework Help, Discussion**