Question

If the road is unbanked and the coefficient of friction between the road and the tyres is $0.8$ , then the maximum speed with which an automobile can move around a curve of $84.5 \, m$ radius without slipping $(g=10\text{ }m{{s}^{-2}})$ is

• A. $26\text{ }m{{s}^{-1}}$
• B. $67.6m{{s}^{-1}}$
• C. $13m{{s}^{-1}}$
• D. $36.7m{{s}^{-1}}$

Answer 1

Answer: (A)

$26\text{ }m{{s}^{-1}}$

Answer 2

$v=\sqrt{\mu Rg}$
or $v=\sqrt{0.8\times 84.5\times 10}$
$=26\,ms{{~}^{-1}}$