a car travels from Chennai To Bengaluru with the speed of 60 km per hour and returns back along the same Path with a speed of 40 km per hour. what is the average speed of the car? (In km/hr)
Answers
Answer:
50 km/hr
Explanation:
Sum of two speeds=60 km/h+40km/hr = 100km/hr
Average speed = 100/2 = 50km per hr
PROCESS
Add the speeds given
Divide them by 2
Given: Distance = d ( same for both journeys)
speed for forward journey - v₁ = 60km/hr
speed for backward journey- v₂ = 40km/hr
To Find: average speed = ?
let time taken for forward journey = t₁
let time taken for backward journey = t₂
Solution: Formula = d = speed × time
t₁ = d/v₁
t₁ = d/60
Similarly,
t₂ = d/v₂
t₂ = d/40
Average speed = Total distance / total time taken(t₁ + t₂) ( does not consider the direction of motion)
Total distance covered = d + d =2d
Total time taken = d/60 + d/40
= 2d + 3d/120
= 5d/120
= d/24 hr
Average speed = 2d/d × 24
= 2 × 24
= 48 km/hr
Hence, average speed of the car = 48 km/hr