A car travels in a flat circle of radius R. At a
certain instant the velocity of the car is 20 m/s
north, and the total acceleration of the car is
2.5 m/s2 37° south of west. Which of the
following is correct ?
(A) R = 0.40 km, and the car’s speed is decreasing
(B) R = 0.20 km, and the car’s speed is decreasing
(C) R = 0.20 km, and the car’s speed is increasing
(D) R = 0.16 km, and the car’s speed is increasing