Question

A car is moving on a horizontal circular road of radius $0.1\, km$ with constant speed. If coefficient of friction between tyres of car and road is $0.4$, then speed of car may be $\left(g=10\, m / s ^{2}\right)$

• A. 5 m / s
• B. 10 m / s
• C. 20 m / s
• D. All of these

Answer 1

Answer: (D)

Maximum speed for the circular road
$\frac{v_{\text {maximum }}^{2}}{r} =\mu g$
$V_{\text {maximum }} =\sqrt{\mu r g}$
$=\sqrt{0.4 \times 100 \times 10}$
$=\sqrt{400}=20\, m / s$