Question

The system shown is in equilibrium in vertical plane. All the rods and the supports A & B are light and friction coefficient between supports and horizontal rod is $\mu$. If maximum value of angle $\alpha$ is ${37}^0$ then find the value of 4$\mu$. Assume light rod exerts force only along the rod.

• A. $2$
• B. $3$
• C. $5$
• D. $1$

Answer 1

Answer: (B)

$3$

Free diagrams of the system is shown in below figure.
$F\sin \alpha =\mu N.......\left(1\right)$
$N=F\cos \alpha .......\left(2\right)$
$F\sin \alpha =\mu F\cos \alpha$
$\tan \alpha =\mu$
when $\alpha =37,\mu =0.75$
$4\mu =3$