Unstable traffic flow occurs when drivers accelerate and brake too often. Unstable traffic flow wastes energy. The table below g
ives one example of traffic speeds, in lometers per hour
), man
o
Time (p.m.)
Speed (km/h)
4.00
30
4.10
20
4:20
50
4:30
70
4:40
20
4:50
7 0
5:00
20
What is the mean speed, in km/h, in this situation?
You may use the calculator
A 20
B 30
C 40
D 50