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Hi,
I'm not used to communicate physics in English, so my language may be a bit off.
This task is fairly simplistic. It's a figure which is held up in points A and B (both having an x and y force exerted on them), and the figure has a joint C. It is depicted in attached files.
The answers are supposed to be F_A = 13,00 kN, F_B = 7,85 kN, F_C = 9,88 kN.
My results are erroneous.
Can anyone please give me some guidance?
Here's my process:
I separate AC from BC and get C with internal forces with equally large opposing forces.
Figure AC:
Sigma M_A (clockwise is +) = 0
5*2 + 10*2  4*C_Ay + 4*C_Ax = 0
=> 30  4C_Ay + 4C_Ax = 0, this is (1)
Figure BC:
Sigma M_B (clockwise is +) = 0
( cos(arctan(3/4)) * 12 * 2,5)  (sin(arctan(3/4)) * 12 * (tan(arctan(3/4)) * 2,5))  C_Bx * 3  C_By *4 = 0
 37,5  3C_Bx  4 C_By = 0, this is (2)
I find an expression for one of the missing values, and put this in the other formula.
And my result is wrong. Always wrong for these tasks. I must do some fundamental error. Any help will be appriciated.
I'm not used to communicate physics in English, so my language may be a bit off.
This task is fairly simplistic. It's a figure which is held up in points A and B (both having an x and y force exerted on them), and the figure has a joint C. It is depicted in attached files.
The answers are supposed to be F_A = 13,00 kN, F_B = 7,85 kN, F_C = 9,88 kN.
My results are erroneous.
Can anyone please give me some guidance?
Here's my process:
I separate AC from BC and get C with internal forces with equally large opposing forces.
Figure AC:
Sigma M_A (clockwise is +) = 0
5*2 + 10*2  4*C_Ay + 4*C_Ax = 0
=> 30  4C_Ay + 4C_Ax = 0, this is (1)
Figure BC:
Sigma M_B (clockwise is +) = 0
( cos(arctan(3/4)) * 12 * 2,5)  (sin(arctan(3/4)) * 12 * (tan(arctan(3/4)) * 2,5))  C_Bx * 3  C_By *4 = 0
 37,5  3C_Bx  4 C_By = 0, this is (2)
I find an expression for one of the missing values, and put this in the other formula.
And my result is wrong. Always wrong for these tasks. I must do some fundamental error. Any help will be appriciated.
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