Question

A car travells first half distance between two
points. lying along a straight line with a speed of
40 Km/hr and rest half with a speed of 60 Km/hr.
Calculate the average speed of the car in the
journey.​

Answer 1

Answer:

48 km/hr

Explanation:

Let the total distance be 'd'

The car is covering 'd/2' distance with 40 km/hr. Let the time taken with this speed be t'.

Therefore, t' = (d/2)/40 => t' = d/80

Then, the car is covering another 'd/2' distance with 60 km/hr. Let the time taken with this speed be t".

Therefore, t" = (d/2)/60 => t" = d/120

Hence, the total time taken in the entire journey (t),

=> t = t' + t"

=> t = d/80 + d/120

=> t = 5d/240 = d/48

Now,

The average speed (v) =

(total distance)/(total time)

=> v = d/(d/48) = 48 km/hr