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 ?

Options

A. `t_(1)` will decrease while `t_(2)` will increase
B. H will increase
C. `R_(1)` will decrease while `R_(2)` will increase
D. T may increase or decrease

Answer

A, D

Explanation

As air drag reduces the vertical component of velocity so time to reach maximum height will decrease and it will decrease the downward vertical velocity hence time to fall on earth increases.