Question

A train covers 1/2 of its journey with a speed of 60m/s and the other 1/2 the speed of 40m/s calculate avg. speed of train during all journey( class 9th)​

Answer 1

Answer:

Let the journey length = 2 d meter

Time taken to cover half the journey at 60 m/s = d meter ÷ 60 meter per second = (d/60) s

Time taken to cover the second half of journey at 40 m/s = d meter ÷ 40 meter per second = (d/40) s

Total time taken for the entire journey of length 2d = d/60 + d/40 = d ( 1/40 + 1/60) = 5d/120 s = d/24 second

Average speed of journey = total journey length of 2d ÷ total time taken = (2 d)/ (d/24) = 48 m/s.

The average speed of the train during the entire journey = 48 m/s.