To determine which cars are either speeding up or slowing down, we need to examine the changes in their velocities over the given 10-second intervals for each car. Essentially, if the starting and ending velocities of a car are different, it means that the car is either speeding up or slowing down.
Let's analyze each car one by one:
1. Car A:
- Starting Velocity: 30 km/h
- Ending Velocity: 30 km/h
Since the starting and ending velocities are the same (30 km/h), Car A is neither speeding up nor slowing down. It maintains a constant speed.
2. Car B:
- Starting Velocity: 0 km/h
- Ending Velocity: 20 km/h
Here, the starting velocity is 0 km/h, and the ending velocity is 20 km/h. Since the velocities are different, Car B is speeding up (from a standstill to 20 km/h).
3. Car C:
- Starting Velocity: 30 km/h
- Ending Velocity: 0 km/h
In this case, the starting velocity is 30 km/h, and the ending velocity is 0 km/h. The change in velocity indicates that Car C is slowing down (coming to a stop from 30 km/h).
4. Car D:
- Starting Velocity: 0 km/h
- Ending Velocity: 0 km/h
With both the starting and ending velocities being 0 km/h, Car D is stationary for the entire interval. It does not speed up or slow down.
Based on the analysis, the cars that are either speeding up or slowing down are:
- Car B (speeding up),
- Car C (slowing down).
Thus, the correct answer is:
[tex]\[ [\text{False}, \text{True}, \text{True}, \text{False}] \][/tex]
