A car driver going at some speed u suddenly finds a wide wall at a distance r. Should he apply brakes or turn the car in a circle of radius r to avoid collapsing with the wall.

Moving in a car if the driver sees the wall suddenly at a distance r then he should turn the car with a velocity such that

frictional force must balance it out, if not it would collapse with the wall. So, it is advisable to turn the car in a circle and also apply the brakes simultaneously to avoid collapsing with the wall. We can derive a mathematical expression for velocity in this situation:


Here friction ≥ centripetal force



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