Question

If the road of the previous problem is horizontal (no banking), what should be the minimum friction coefficient so that a scooter going at 18 km/h does not skid?

• A. 0.15
• B. 0.2
• C. 0.25
• D. 0.5

Answer 1

The correct option is C 0.25

Given : $r=10$ m

Average speed of the vehicle $v=18km/hr=18\times \frac{5}{18}=5$ $m/s$

The centripetal force provide the required fraction force so the scooter does not slide i.e $m{a}_r=f$

$\therefore$ $\frac{m{v}^2}{r}=\mu mg$

For no skidding $\mu =\frac{v^2}{gr}$

$\therefore$ $\mu =\frac{5^2}{10\times 10}$ $⟹\mu =0.25$