Final answer:
The correct answer is D. Speed = 2.19 km/hour, which is found by dividing the total distance (3.5 km) by the total time (1.6 hours), resulting in an average speed calculation.
Step-by-step explanation:
The question asks us to determine the average speed at which Sierra, Sarah, and Samuel were walking when they went around a block. To find the average speed, we use the formula: Average speed = Total distance traveled / Total time taken.
In this scenario, the total distance traveled is 3.5 km, and the total time taken is 1.6 hours. Plugging these values into the formula gives us: Average speed = 3.5 km / 1.6 hours.
This calculation produces a result of 2.1875 km/hour, which, when rounded to two decimal places, is 2.19 km/hour. Therefore, the correct answer is:
D. Speed = 2.19 km/hour
To further clarify, let's look at some similar examples:
• If James took 3,600 seconds (1 hour) for a round trip, his average speed is the total distance divided by the total time.
• When comparing the average speed of different individuals, such as Terri, Aaron, and Jamal, you would calculate their individual speeds and then rank them.
• For Cassie walking at 1.40 m/s for a distance of 205 m, the time taken would be calculated using the average speed equation.
• The displacement for a round trip is zero because the start and end points are the same, but the average speed is calculated using the round trip's total distance and time.
Remember to always check if your answer is reasonable based on estimated speeds and contextual information provided by the problem.