Question

Consider the following frame

$\text{If}{M}_{OB}=40kNm$

$M_{OD}=-20kNm$

$M_{OC}=30kNm$


$\text{then the value of}{M}_{AO}iskNm\left(inmagnitudeonly\right)$

• A. 25

Answer 1

The correct option is A 25
As per joint equilibrium condition at joint O

$\therefore M_{OA}+M_{OB}+M_{OC}+M_{OD}=0$

$\therefore M_{OA}+40+30-20=0$
$M_{OA}=-50kNm$

Then,
$M_{AO}=\frac{1}{2}{M}_{AO}=-25kNm$