Question

Calculate the maximum speed of a car which makes a turn of radius 100 m
on a horizontal road. The coefficient of friction between the tyres and the
road is 0.90. Take g = 10 ms–2.

Answer 1

answer : 30m/s

explanation : The force of static friction that keeps pushing the car towards the centre of curvature. or you can say, static friction provides the necessary centripetal force to turn the car on horizontal road.

static friction = centripetal force

⇒μ mg = mv²/R

⇒μg = v²/R

⇒v² = μgR

⇒v = √{μgR}

hence, maximum speed of car which makes a turn on horizontal road is v = √{μgR}

given, μ = 0.9, g = 10m/s² and R = 100m

so, v = √{0.9 × 10 × 100} = √(900) = 30m/s

hence, maximum speed of car is 30m/s