When a car corners at speed one is relying on thefriction between the tyres and the road to counter the centrifugalforce tending to throw the car outwards. One way to reduce thedependence on friction is to ‘bank’ the corner. For a cartravelling with a speed v entering a corner of radius r, show thatthe angle of the bank, θ, (measured from the horizontal) shouldsatisfy tanθ = v2/(gr) if there is to be no reliance on friction.In the light of this result discuss the design of the ‘Wall ofDeath’ fairground attraction in which a motorbike is ridden atspeed around the inner surface of a large vertical cylinder, withthe bike and rider at a small angle to the horizontal plane. Whatrole does friction play and why is a small anglenecessary?
