A man walks on a straight road from his home to market 2.5 km away with speed of 5 km/h Finding the market closed, he instantly turns and walks back with a speed of 7.5 km/h. What is the magnitude of average velocity and average speed of the man over the interval of time (i) 0 to 30 min (ii) 0 to 50 min (iii) 0 to 40 min ?

Explanation

0 to 30 min, Average speed `=2.5 km"/"30` min `= 5 kmh^(-1)`.
Average velocity `= 5 kmh^(-1)`. Because this interval distance travelled and magnitude of displacement are equal.