Question

what is the average speed of a person travelling half the distance with speed of 20m/s and other half at speed of 30m/s

Answer 1

let total distance be 2n metre  then, half of the distancewill be= n metre  as time=distance/speed  thus, then time taken to travel 1st half and 2nd half distance would be (n/20)s and (n/30)s respectively.  then total time taken= (n/20)s + (n/30)s                                      = (5n/60)s  therefore, average velocity= distance in a particular direction/time                                                = 2n metre divided by (5n/60)s                                                = 24m/s