The stiffened cross-section of a long slender uniform structural member is idealized as shown in the figure below. The lumped areas at $\mathrm{A}, \mathrm{B}, \mathrm{C}$ and $\mathrm{D}$ have equal cross-sectional area of $3 \mathrm{~cm}^{2}$. The webs $\mathrm{AB}, \mathrm{BC}, \mathrm{CD}$ and $\mathrm{DA}$ are each $5 \mathrm{~mm}$ thick. The structural member is subjected to a twisting moment of $10 \mathrm{kNm}$. The magnitudes of the shear flow in the webs, $q_{A B}, q_{B C}, q_{C D}$, and $q_{D A}$ in $\mathrm{kN} / \mathrm{m}$ are, respectively

(A) 20,20,20,20

(B) 0,0,50,50

(C) 40,40,0,0

(D) 50 , $, 50$

The stiffened cross-section of a long slender uniform structural member is idealized as shown in the figure below. The lumped areas at $\mathrm{A}, \mathrm{B}, \mathrm{C}$ and $\mathrm{D}$ have equal cross-sectional area of $3 \mathrm{~cm}^{2}$. The webs $\mathrm{AB}, \mathrm{BC}, \mathrm{CD}$ and $\mathrm{DA}$ are each $5 \mathrm{~mm}$ thick. The structural member is subjected to a twisting moment of $10 \mathrm{kNm}$. The magnitudes of the shear flow in the webs, $q_{A B}, q_{B C}, q_{C D}$, and $q_{D A}$ in $\mathrm{kN} / \mathrm{m}$ are, respectively

(A) 20,20,20,20

(B) 0,0,50,50

(C) 40,40,0,0

(D) 50 , $, 50$

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