Question

A car starts from rest to cover a distance s. The coefficient of friction between the road and the tyres is m. The minimum time in which the car can cover the distance is proportional to-

• A. m
• B. $\sqrt{\mu}$
• C. $\frac{1}{\mu}$
• D. $\frac{1}{\sqrt{\mu}}$

Answer 1

Answer: (D)

$\frac{1}{\sqrt{\mu}}$

Answer 2

Max. retardation

a = $\frac{\mu mg}{m}$= mg

Q S = $\frac{1}{2}$at² Ž t = $\sqrt{\frac{2S}{a}}$

\f0 t_min = $\sqrt[\sqrt{\frac{2S}{\mu g}}]{\frac{2S}{a_{\max}}}$ Ž t_min µ $\frac{1}{\sqrt{\mu}}$