Moment Problem: Solving for the Resultant Force and Moment at Point C

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SUMMARY

The discussion focuses on solving the moment problem related to a small boat suspended from two davits, specifically calculating the moment about point C of the resultant force Ra exerted on the davit at point A. The tension in line ABAD is given as 369 N. The user initially calculated the force vector and attempted to find the cross product with the davit direction vector but encountered discrepancies in the i-component of the result. Clarifications were provided regarding the orientation of the distance and the interpretation of the forces acting at point A.

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moment problem please help

Homework Statement



a small boat hangs from two davits one of which is shown in the figure. the tension in line ABAD is 369 N. Determine the moent about C of the resultant force Ra exerted on the davit at A

Homework Equations





The Attempt at a Solution


ok so first i took the 369N and multiplyed it by the unit vector
(2.4i-3.1j-1.2k)/(2.4^+3.1^2+1.2^2)^.5 and got (216,-279,-108)
ok then i took the cross product of (216,-279,-108) and (-2.4,0,0)when i did this i got (0,-259.2,670)but the i component shouldn't be zero please help
 

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That distance of 3.1 meters doesn't look like it's parallel to the y-axis, but you're treating it as though it is parallel to it. Is it supposed to be vertical?
 
Also, if "line ABAD" means the rope is double between A and B (as in your figure) there are three forces of 369N at point A, not one.
 

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