How do you calculate the moment of a force about a point?

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SUMMARY

The discussion focuses on calculating the moment of a force about a point, specifically point O, using the formula Moment = Perpendicular Force * distance. Participants emphasize the necessity of determining the angle between the force and the rod to find the perpendicular component of the force. The correct approach involves calculating the angle that the force makes with the horizontal direction to accurately compute the moment. Incorrect attempts using cosine and sine functions without proper angle determination led to erroneous results.

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Homework Statement


http://imgur.com/7DDxqJp
Find the moment generated about point O by the force, F1.

Homework Equations


Moment = Perpendicular Force * distance

The Attempt at a Solution


I tried plugging in that, because sqrt(3^2+4^2)=5, that my result would be either 6cos(30)*5 or 6sin(30)*5, but both of those answers are wrong
 
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You need to find the component of the force that is perpendicular to the rod. So, you will need to find the angle between the force and the rod. It might help if you first find the angle that the force makes with respect to the horizontal direction (x direction).
 

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