Question

Determine the value of shear force at point A in the figure shown below.

• A. wl/6
• B. wl/2
• C. wl/3
• D. wI

Answer 1

Answer:

C. wl/3

Taking moment about B:

$R_A L=\frac12WL\times \frac {2L} {3} \Rightarrow R_{A} =\frac{WL}{3}$

$R_{B} =\frac12 WL - R_{A} = \frac12WL- \frac{W L}{ 3} = \frac{WL}{ 6}$

$F_{x} = - R_{B} +\frac 12 \frac{wx}{L} \times x = -\frac {WL}{6} + \frac{w x ^ 2}{2L}$

At $x = L : F_{A} =\frac {WL}{3}$