What Are the Correct Tension Forces in Cables Lifting a 8Mg Tractor?

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The discussion focuses on calculating the tension forces in cables AB, AC, and AD required to lift an 8Mg tractor. The user has derived unit vectors for the cable forces and set up equations based on these vectors. They calculated the magnitudes of the forces but found discrepancies in their results. The user is seeking assistance to identify errors in their calculations. Clarification on the correct approach to solving the problem is requested.
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A tank hanging off a hook, what are the tension forces?

Homework Statement


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Determine the forces in cables AB, AC and AD needed to lift the tractor which has a mass of 8Mg.


Homework Equations





The Attempt at a Solution


I found the unit vectors of the three rope forces using the ropes' position vectors.

B = [-0.5241i -0.3276j -0.7861k]
C = [-0.5241i 0.3276j -0.7861k]
D = [0.31623i 0j -0.9487k]

So F_B = -9.8bB, F_C = -9.8cC and F_D = -9.8dD where b, c, d = magnitudes of the forces

Then I set up a system of equations to find b, c and d. I found:
b = c = -1.691Mg
d = -5.6218Mg

|F_b| = |F_c| = 9.8*1.691E6 = 1.66E7 N
|F_d| = 9.8*5.6218E6 = 5.51E7 N

But I checked and they aren't the right answers. What did I do wrong?
 
Last edited:
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Can no one help? :(
 
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