Car is driven first 2.0 hour at the velocity 40 km/h.
We know,
Distance covered = Velocity * time.
Therefore, distance covered by car in first two hours = 40 * 2.0 = 80 km.
Car is driven second 2.0 hour at the velocity 60 km/h.
Therefore, distance covered by car in first two hours = 60 * 2.0 = 120 km.
Total distnace covered = 80 km + 120 km =200 km.
Total time taken = 2.0 + 2.0 = 4.0 hours.
Average velocity = [tex]\frac{Total \ distance \ covered }{Total \ time \ taken }[/tex]
Plugging values in above formula, we get
[tex]= \frac{200}{4}[/tex]
= 50 km/h
Therefore, average velocity is 50 km/h.
