Question

A car covers first half of the distance between two places at a speed of 40km/hr and the second half at 60km/hr. Calculate the average speed of the car

Answer 1

Answer:

Average speed of the car = 48 km/h

Step by step explanations :

Given that,

A car covers first half of the distance between two places

at a speed of 40km/hr

and the second half at 60km/hr

let the total distance be 2d

here,

time taken to cover d at 40 km/h

= d/40

time taken to cover d at 60 km/h

= d/60

Average speed =

total distance covered/total time taken

total distance covered = 2d

total time taken =

d/40 + d/60

= (3d + 2d) /120

= 5d/120

= d/24 h

so,

Average speed = 2d/(d/24)

= 48d/d

= 48 km/h

so,

Average speed of the car = 48 km/h

Answer 2

Answer:

Average speed of car = 48 km/h

Step by step explanations :

Here,

Velocities given =

40 km/h for 1st half and

60 km/h for 2nd half

let V1 = 40 km/h

V2 = 60 km/h

Average speed = 2V1V2/(V1 + V2)

= 2(60)(40)/(40 + 60)

= 80 × 60 /100

= 48 km/h

so,

Average speed = 48 km/h