Answer:
Speed = 0.1333 km/minute
Step-by-step explanation:
According to the graph :
At 10 minutes, it could be observed that the Distance moved started to reduce until distance moved reached 0 at 20 minutes. This could be interpreted as a case of negative acceleration (that is deceleration) whereby the distance covered started to decrease with time until the it rest at 0.
Speed during the last 30 minutes :
Speed = distance / time
Distance moved during this period :
Distance (from 0 to 4km)
Time = (from 30 to 60 minutes)
Speed = (4 - 0) / (60 - 30)
Speed = 4 / 30
Speed = 0.13333 km per minute
