3. A car travels three-quarters of the way around a circle of radius 20 m in a time of 3 s at constant speed. The initial velocity is west and the final velocity is south. (a) Calculate the average velocity for this trip. (b) Calculate the car's average acceleration during this 3 s. (c) Explain how a car moving a constant speed has a nonzero average acceleration. [Answer: (a) 9.4 m/s at 45° north of east (b) 15 m/s² at 45° south of east]

3. A car travels three-quarters of the way around a circle of radius 20 m in a time of 3 s at constant speed. The initial velocity is west and the final velocity is south. (a) Calculate the average velocity for this trip. (b) Calculate the car's average acceleration during this 3 s. (c) Explain how a car moving a constant speed has a nonzero average acceleration. [Answer: (a) 9.4 m/s at 45° north of east (b) 15 m/s² at 45° south of east]