>> Study Material
>> IIT JEE Physics
>> Newtons Laws of Motion
>> Banking of Roads-1
Banking of Roads
Perhaps you have noticed that when a road is straight, it is horizontal too. However, when a sharp turn comes, the surface of the road does not remain horizontal. This is called banking of the roads.
|| 1 | | 2 | | 3 | | 4 | | 5 |
Purpose of banking
Banking is done
1. To contribute in providing necessary centripetal force.
2. To reduce frictional wear and tear of tyres.
3. To avoid skidding
4. To avoid overturning of vehicles.
Case I: μ = 0
What we really wish is that even if there is no friction between the tyres and the road, yet we should be able to take a round turn. In the given figure Vertical N cos θ component of the normal reaction N will be equal to mg and the horizontal N sin θ component will provide for the necessary centripetal force. [Please note that as we are assuming μ to be zero here, the total reaction of the road will be the normal reaction.] Frictional forces will not act in such a case.
.·. N cos θ = mg .......... (i)
N sin θ = mv2/r .......... (ii)
Dividing equation (ii) by (i), we get
tan θ = v2/rg
where θ is the angle of banking.