Given: A man walks 7 km in 2 hrs
Later he walks 2 km in 1 hour
We need to find the average speed and average velocity
We know that
Speed = Total distance / Total time
Total distance travelled by man = 7 km + 2 km = 9 km
Total time taken = 2 + 1 = 3 hrs
Average speed = 9/3 = 3 km/hour.
Velocity = Total displacement / Total time
Average velocity will be the same as average speed in this case since there is no direction change mentioned.
Therefore Total Displacement = Total Distance
average velocity = average speed = 3 km/hour.
Average speed = 3 km/hr.
Average velocity = 3 km/hr.