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

Answer

B

Explanation

The road is horizontal (no banking)
and `(mv^2)/R=muN`
`N=mg`
So `(mv^2)/R=mumg`

Here `v=5m/sec, R=10 m
`:. 25/10 =mug`
`rarr mu=(25/100)=0.25`