Velocity = displacement / time
Displacement = 2.3 km
Time = 5.78 mins
Velocity = 2.3/5.78
Velocity = 0.398 to the nearest 3 significant figures
Answer:
The average velocity is 180 km/hr
Explanation:
Given;
initial velocity, u = 60 km per hour
final velocity, v = 120 km per hour
initial time = 1 hour
final time = 2 hour
Initial position = 60 km/h x 1 hour = 60 km
final position = 120 km/h x 2 hour = 240 km
The average velocity is given by;

Therefore, the average velocity is 180 km/hr
Do you have any other information? Like the velocity of the wave?