- #1
Bradracer18
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Homework Statement
Ok, I've got three cables all pointing in a downward direction towards the orgin. They all connect at the orgin, onto a 750lb weight. Determine the tensions in A,B,C.
I'm going to put these into (x,y,z) form, so you get the picture.
A = (4,-2,5)
B = (-3,-3,6)
C = (-4,3,4)
Homework Equations
The Attempt at a Solution
Ok, I've tried this...not sure if its right, but seems right to me. And...if so, I'm stuck at the point of how to solve the 3 equations and 3 unknowns. I can't remember how to do that. Ok here goes...I hope this isn't complicated.
R = sum(F) = Ta + Tb + Tc = 0
Ta = Ta(4i - 2j +5k/sqrt(45))
Tb = Tb(-3i - 3j +6k/sqrt(54))
Tc = Tc(-4i + 3j +4k/sqrt(41))
Skip a step here...
R = (0.5963Ta - 0.4082Tb - 0.6247)i + (-0.2981Ta - 0.4082Tb + 0.4685Tc)j + (0.7454Ta + 0.8165Tb +0.6247Tc)k
Sum(Fx) = 0.5963Ta - 0.4082Tb - 0.6247Tc = 0
Sum(Fy) = -0.2981Ta - 0.4082Tb + 0.4685Tc = 0
Sum(Fz) = 0.7454Ta + 0.8165Tb + 0.6247Tc = 0
I'm stuck here. Also...I'm wondering...in my sum(Fz), I think this is where I'd subtract 750...as it is pointing down in the z direction. Is this correct?
Thanks in advance