The problem describes an example of traffic speeds in an unstable flow situation over a specific period in the afternoon. Let's break down the information provided in the table:
### Information from the table:
| Time (p.m.) | 4:00 | 4:10 | 4:20 | 4:30 | 4:40 | 4:50 | 5:00 |
|-------------|------|------|------|------|------|------|------|
| Speed (km/h)| 30 | 20 | 50 | 70 | 20 | 70 | 20 |
### Step-by-Step Detailed Solution:
1. Read the given times and speeds:
- Time: 4:00 p.m., 4:10 p.m., 4:20 p.m., 4:30 p.m., 4:40 p.m., 4:50 p.m., 5:00 p.m.
- Speed corresponding to each time in km/h:
- 4:00 p.m.: 30 km/h
- 4:10 p.m.: 20 km/h
- 4:20 p.m.: 50 km/h
- 4:30 p.m.: 70 km/h
- 4:40 p.m.: 20 km/h
- 4:50 p.m.: 70 km/h
- 5:00 p.m.: 20 km/h
2. Interpreting the speeds:
- The traffic speeds vary considerably over the given period.
- There are instances of both high speeds (e.g., 70 km/h) and low speeds (e.g., 20 km/h) indicating frequent acceleration and braking.
3. Analyze the variability of speeds:
- From 4:00 to 4:10, speed decreases from 30 km/h to 20 km/h.
- From 4:10 to 4:20, there is a sharp increase from 20 km/h to 50 km/h.
- From 4:20 to 4:30, the speed increases further from 50 km/h to 70 km/h.
- From 4:30 to 4:40, there is a significant drop from 70 km/h to 20 km/h.
- From 4:40 to 4:50, speed once again increases from 20 km/h to 70 km/h.
- From 4:50 to 5:00, the speed decreases again from 70 km/h to 20 km/h.
4. Conclusion:
- The speeds show significant fluctuations over the one-hour period from 4:00 p.m. to 5:00 p.m.
- Such variations indicate unstable traffic flow, where drivers frequently accelerate and brake, leading to inefficient energy usage.
By examining the given times and corresponding speeds, we can clearly observe the unstable traffic flow characterized by frequent changes in speed. The fluctuations in speed are a textbook example of how unstable traffic patterns can occur, demonstrating the challenges of maintaining a steady and efficient traffic operation in such conditions.
