1. **State the problem:** Calculate the magnitude of the average velocity of Al Unser driving one complete lap around a 2.50 mile track in 38.54 seconds, expressed in km/hr. 2. **Recall the formula for average velocity magnitude:** $$\text{Average velocity magnitude} = \frac{\text{displacement}}{\text{time}}$$ 3. **Important note:** Since the track is a complete lap (oval), the displacement is zero because the start and finish points are the same. Therefore, the magnitude of average velocity is zero. 4. **However, if the problem intends average speed (total distance over time), then:** - Convert distance from miles to kilometers: $$2.50 \text{ miles} \times 1.60934 = 4.02335 \text{ km}$$ - Convert time from seconds to hours: $$38.54 \text{ s} \times \frac{1}{3600} = 0.0107056 \text{ hr}$$ - Calculate average speed: $$\frac{4.02335}{0.0107056} \approx 375.9$$ 5. **Final answer:** The magnitude of average velocity (displacement/time) is $0$ km/hr. If average speed is intended, it is approximately $376$ km/hr. Since the question asks for average velocity magnitude, the correct answer is $0$ km/hr.