Question

A superspeedway in New delhi has among the highest super- elevation rates of any track on the Indian Grand Prix circuit. The track requires drivers to negotiate turns with a radius of 335 m and ${33}^{\circ }$ banking. Given this information, the coefficient of side friction required in order to allow a vehicle to travel at 320 km/h along the curve is

• A. 1.761
• B. 0.176
• C. 2.530
• D. 0.253

Answer 1

The correct option is A 1.761

R = 335 m

V = 320km/hr

$e+f=\frac{v^2}{127R}$

$\Rightarrow f=\frac{v^2}{127R}-e$

$=\frac{{320}^2}{127\times 335}-\tan {33}^{\circ }$

$=1.761$

Note : While deriving the above equation, we consider $1-ef\simeq 1$ but this is not valid in this case because banking provided is very high $(tan{33}^{\circ }=0.65).$ So formula used should be

$\frac{e+f}{1-ef}=\frac{V^2}{127R}$

Which will result in f = 0.685.