Question

A car is moving on a circular level road of curvature 300 m. If the coefficient of friction is $0.3$ and acceleration due to gravity is $10\,m\, s^{-2}$, the maximum speed of the car can be

• A. $90\, km\, h^{-1}$
• B. $81\, km\, h^{-1}$
• C. $108\, km\, h^{-1}$
• D. $162\, km\, h^{-1}$

Answer 1

Answer: (C)

Here, $R = 300 \,m, m = 0.3, g = 10 \,m \,s^{-2}$
The maximum speed of the car is
$\upsilon_{max}=\sqrt{\mu\,Rg}=\sqrt{0.3\times300\,m\times10\,m\,s^{-2}}$
$=30\,m\,s^{-1}=30\times\frac{18}{5}km\,h^{-1}=108\,km\,h^{-1}$