Question

On a circular curve, the rate of superelevation is e. While negotiating the curve a vehicle comes to a stop. It is seen that the stopped vehicle does not slide inwards (in the radial direction). The coefficient of side friction is f. Which of the following is true ?

• A. $e\le f$
• B. $f<e\le 2f$
• C. None of these
• D. $e\ge 2f$

Answer 1

The correct option is A $e\le f$



For equilibrium,

$fN\ge mgsin\theta$

$\Rightarrow fmgcos\theta \ge mgsin\theta$

$\Rightarrow fcos\theta \ge sin\theta$

$\Rightarrow f\ge tan\theta$

$\Rightarrow f\ge e$

$\text{or}e\le f$