Question

A rigid bar AC is supported by three rods of same· material and of equal diameter. The bar AC is initially horizontal. A force P is applied such that the bar AC continues to remain horizontal. Forces in each of the shorter bars and in the longer bar are, respectively

• A. $0.4P,0.2P$
• B. $0.3P,0.4P$
• C. $0.2P,0.6P$
• D. $0.5P,zero$

Answer 1

The correct option is A $0.4P,0.2P$

The elongation of all the bars will be same.
$\Delta =\frac{P_1{L}_1}{EA}=\frac{P_2\left(2L_1\right)}{EA}$
$\therefore P_2=0.5P_1$
$P_2+P_1+P_1=P$
$P_1=0.4P$ (shorter bar)
$P_2=0.2P$ (longer bar)