21. The coefficient of friction acting upon a 1500 kg car is 0.75. The car is making a 180-degree turn around a curve with
a radius of 25 meters. Determine the maximum speed with which the car can make this turn.
a. 187.5 m/s
b. 209.44 m/s

c. 13.69 m/s
d. 7.5 m/s