Question

A person wants to drive on the vertical surface of a large cylindrical wooden 'well' commonly known as death well' in a circus. The radius of the well is R and the coefficient of friction between the tyres of the motorcycle and the wall of the well is ${\mu }_s$. The minimum speed, the motorcycle must have in order to prevent slipping, should be

• A. $\sqrt{\frac{Rg}{{\mu }_s}}$
• B. $\sqrt{\frac{{\mu }_s}{Rg}}$
• C. $\sqrt{\frac{{\mu }_{s}g}{R}}$
• D. $\sqrt{\frac{R}{{\mu }_{s}g}}$

Answer 1

The correct option is A $\sqrt{\frac{Rg}{{\mu }_s}}$

$N=\frac{m{v}^2}{R},\text{mg}={\mu }_{s}N=\frac{{\mu }_{s}m{v}^2}{R}$
$\therefore v=\sqrt{\frac{Rg}{{\mu }_s}}$