How to get mag. & angles of resultant couple moment

[caddyguy109]

I have another thread for another problem, but no one seems to be responding about this second problem, so i'll post it here.

Need to find the magnitude and direction/space angles of the resultant couple moment of two valve handles being turned, as pictured:
http://img347.imageshack.us/img347/2488/problem64sx.jpg

Would the resultant mean at the origin of the axes? So far, I've done this, using the left as A and the right as B:

M=(d)(F)
MA=(0.175m)(35N)=6.125Nm
MB=(0.175m)(25N)=4.375Nm

Should the forces have unit vectors k on them? If what I did is somewhat right, then how do I get the resultant magnitude and direction if the only other piece of data given is that the wheel on the right is angled 60deg. from the y-axis--no other distances, etc?

 

[Doc Al]

Your magnitudes are correct, but these moments are vectors. What direction do they point? ($\vec{M} = \vec{r} \times \vec{F}$) Add those vectors.

(And please don't post the same question in mutliple threads! It's generally best to post one problem per thread.)

 

[quicknote]

To find the magnitude and direction/space angles of the resultant couple moment, you will need to use vector addition and trigonometry. First, you will need to determine the individual moments of each valve handle, as you have already done for MA and MB. These moments represent the magnitude and direction of the forces applied by each handle.

Next, you will need to use vector addition to find the resultant moment. This can be done by adding the individual moments using the parallelogram method or by using the Pythagorean theorem and trigonometry. Once you have the resultant moment, you can use trigonometry to find the direction or space angles of the moment.

As for the unit vectors, it depends on how you are representing your forces. If you are using Cartesian coordinates, then your forces should have unit vectors. If you are using polar coordinates, then unit vectors are not necessary.

It is important to note that the resultant moment will not necessarily be at the origin of the axes. It will depend on the location of the applied forces and their directions.

If you are still having trouble finding the resultant moment, it may be helpful to consult with a colleague or seek assistance from a professor or tutor. Additionally, there are many online resources and tutorials available that can provide step-by-step instructions for solving vector problems.