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. E) R = 0.16 km, and the car's speed is decreasing.

Question

Quizplus · Accepted Answer

The radial component of acceleration is centripetal, and the tangential component affects speed. Given the direction of total acceleration, the tangential component is opposite to velocity, indicating decreasing speed. Solving for R using centripetal acceleration gives 0.20 km.

A Car Travels in a Flat Circle of Radius R