Question

Keeping the banking angle same to increase the maximum speed with which a car can travel on a curved road by 10%, the radius of curvature of road has to be changed from $20m$ to

• A. $16m$
• B. $18m$
• C. $24.25 ⥂ m$
• D. $30.5\mspace{6mu} m$

Answer 1

Answer: (C)

$24.25 ⥂ m$

Answer 2

$\tan\theta = \frac{v^{2}}{rg}$ ⇒ $r \propto v^{2}$ (if $\theta$is constant)

$\frac{r_{2}}{r_{1}} = \left( \frac{v_{2}}{v_{1}} \right)^{2} = \left( \frac{1.1v}{v} \right)^{2}$= 1.21 ⇒ r₂ = 1.21 × r₁ = 1.21 × 20 = 24.2 m