What is the radius of the circle?

Question

A car is turning on a circular path with a constant speed of 7 m/s. If the car mass is 1200 kg and the coefficient of static friction is between the cars tires and the road .68 what is the radius of the circle?

Answer 1

In this problem, friction is the centripetal force that keeps the car in a circle.  Set the friction equal to the centripetal force, and get the radius from the resulting equation.

 

mv²/r = μmg ⇒

 

r = v²/(μg)

 

Just plug in the numbers.