Question

A particle covers first half of distance with speed 40km/h and rest half with speed of 90m/s. calculate average speed of the journey.​

Answer 1

Explanation:

Avg speed=

total distance covered/ total time taken

Suppose the total distance=s

Time taken for first half t1=distance/speed=(s/2)/v1

=S/2v1

Time taken for second half=s/2v2

Total time=s/2v1)+(s/2v2)=s/2(1/v1+1/v2)

=S(v1+v2)/2v1v2

Avg speed= S/ total time taken

By solving this you get

Avg speed=2v1v2/(v1+v2)

So for this question=

2″40″60/100=48m/s