A man walks on a straight road from his home to a moardet `3 km` away with a speed of`6 km//h`. Finding the market closed, he instantly turns and walks back with a speed of `9 km//h`. What is the (a) magnitude of average velocity and (b) averge speed of the man, over the interval of time (i) `0 to 30 min`, (ii) `0to 50 min`, (iii) `0 to 40 min`?

Explanation

(a) `5km h^(-1), 5km h^(-1)`, (b) `0.6 km h^(-1)`, (c ) `(15)/(8)km h^(-1), (45)/(8) km h^(-1)`