1. At t = 20s, the average speed is 12 km.
2. At t = 30s, the average speed is 20 km.
3. The acceleration between 20s and 30s is 8 km.
4. At t = 40s, the average speed is 30 km.
5. At t = 60s, the average speed is 56 km.
6. The acceleration between 40s and 60s is 26 km.
7. The object is not accelerating at a constant rate.
