Final answer:
The average speed for the entire trip, including time spent stationary at the drive-thru, is calculated as the total distance traveled (3000 meters) divided by the total time in seconds (600 seconds), resulting in an average speed of 5 meters per second (m/s).
Step-by-step explanation:
To calculate the average speed of the entire trip to McDonald's and back, we need to consider the total distance traveled and the total time taken, including the time spent going through the drive-thru. Since the trip to McDonald's is 1500 meters and the trip back is another 1500 meters, the total distance traveled is 3000 meters. The time spent driving is 3 minutes to McDonald's and another 3 minutes back, for a total of 6 minutes. The 4 minutes at the drive-thru do not involve travel, so it does not affect the total distance but does affect the total time. Therefore, the total time is 6 minutes driving and 4 minutes stationary, for a 10-minute total.
First, we must convert 10 minutes into seconds to use meters per second (m/s) for speed. There are 60 seconds in a minute, so 10 minutes is 600 seconds.
The formula for average speed is distance divided by time.
Using the information:
- Distance = 3000 meters
- Time = 600 seconds
The average speed Vavg = Distance / Time = 3000 meters / 600 seconds = 5 m/s.