Homework Help: Analytical Vector methods for a four bar linkage

1. Mar 21, 2013

painkiller72

1. The problem statement, all variables and given/known data
In a four bar linkage r0=30mm, r1=10mm, r2=35mm, r3=20mm and theta1=45 degrees. Calculate theta2, theta3, Vc, W2, and W3 assuming that W1=30 rad/s ccw.

2. Relevant equations
R1*costheta1 + R2*costheta2 - R3*costheta3 - R0*costheta0 = 0 (3-x)
R1*sintheta1 + R2*sintheta2 - R3*sintheta3 - R0*sintheta0 = 0

3. The attempt at a solution
I wasn't sure about this equation from the start since I think it relies on knowing two angles and I only know one.
I first plugged in for
10*cos45+35*costheta2-20*costheta3-30*costheta0
10*sin45+35*sintheta2-20*sintheta3-30*sintheta0
equals
5.252+35*costheta2-20*costheta3-30*costheta0
8.509+35*sintheta2-20*sintheta3-30*sintheta0

and I'm already wondering what I should do from here.

2. Mar 21, 2013

SteamKing

Staff Emeritus
A picture of the linkage would be nice.

3. Mar 23, 2013

painkiller72

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted