Vehicle behaviour on horizontal curves If the centrifugal force on a vehicle negotiating a horizontal curve exceeds the available lateral friction, the vehicle will most likely:

Difficulty: Easy

Correct Answer: skid

Explanation:

Introduction / Context:On horizontal curves, lateral equilibrium is provided by a combination of superelevation and lateral friction between tire and pavement. When the required centripetal force exceeds what friction (and superelevation) can supply, loss of lateral control occurs.

Given Data / Assumptions:

  • Vehicle negotiates a curve of given radius at a given speed.
  • Lateral friction factor f represents peak available friction.
  • Superelevation may be present but is insufficient to balance demand.

Concept / Approach:The demand is v^2 / r. The supply is g*(e + f) in normalized form, where e is superelevation (as a ratio) and f is friction factor. If v^2/(g r) > e + f, the pavement–tire interface cannot transmit the needed lateral force, leading to side slip or skid.

Step-by-Step Solution:

Compute demand ratio: v^2/(g r).Compute supply: e + f.If demand > supply → loss of lateral grip → skid.

Verification / Alternative check:Design formula e + f = V^2/(225R) (with V in km/h, R in m) expresses the same balance; demand exceeding supply signals skidding risk.

Why Other Options Are Wrong:“Slip” is a vague term; “not be affected/none” contradicts physics when demand exceeds resistance.

Common Pitfalls:Ignoring wet pavement which lowers f; assuming e alone can compensate indefinitely; using improper units.

Final Answer:skid

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