Answer
Radius is 421 m.
Explanation
A car with a mass of 1,500 kg requires a centripetal force of 640 N to safely follow a circular curve in the road at 13.4 m/s. Therefore, for radius we use formula which is Fc = mv ^ 2 / r,
As mass = m = 1500kg,
Centripetal force = Fc = 640N,
Velocity = v = 13.4 m / s
By putting values, Fc = mv ^ 2 / r,
r = mv ^ 2 / Fc,
=> r = ( 1500kg ) . ( 13.4 m / s) ^ 2 / 640,
=> r = ( 1500kg ) . ( 179.56 ) / 640,
r = 269340 / 640,
=> r = 420.84 m.
Radius is 421 m.