Question

A car covers the first half of a distaance between two places at a speed of 48ms and and the second half at 60ms calculate the average speed of the car

Answer 1

2v1xv2/v1+v2=2x48x60/48+60

Answer 2

Consider, half of the distance = d, so total distance = d + d = 2d

In first half, his time taken=d/48

In second half, his time taken=d/60

So, Average Speed = Total distance/total time

                                =2d/(d/48 + d/60)

                                =480/9

                                =53.3 m/s