Q 3.13 A man walks on a straight road from his home to a market 2.5 km away with a speed of 5 km h-1. Finding the market closed, he instantly turns and walks back home with a speed of 7.5 km h-1. What is the
(a) magnitude of average velocity, and
(b) average speed of the man over the interval of time
(ii) 0 to 50 min,
(a).(ii) Time taken by the man to reach the market is t1= 30 minutes.
Time taken by the man to reach back home is t2
t1+t2=50 min
Displacement in 50 minutes is d2=0 km
Magnitude of average velocity=d2/(t1+t2)= 0 km h-1
(b).(ii) Distance travelled in 50 minutes is s2=5 km
Average speed=s2/(t1+t2)= 0.6 km h-1