Question

A person is in contact with the inner wall of a vertical hollow cylinder of radius $1m$, remains in equilibrium without slipping down as the cylinder is rotated about its own vertical axis with an angular velocity $3.5rad/s$. The minimum coefficient of static friction between person and wall of cylinder such that the person does not slip down is:

• A. $0.2$
• B. $0.4$
• C. $0.6$
• D. $0.8$

Answer 1

The correct option is D $0.8$

Max. $fs=\mu N=Mg$
Also $N=M{\omega }^{2}R$
$\therefore \mu [M\times (3.5{)}^2\times \left(1\right)]=M\times 10$
$\Rightarrow \mu =0.8$