Question

A car covers half of the distance with speed
60 km/hr and rest of the half with speed
30 km/hr. The average speed of the car is -
(1) 45 km/hr
(2) 40 km/hr
(3) 20.0 km/hr
(4) 50 km/hr​

Answer 1

Answer:

here is your answer ⏩

let, v1=60km/h,v2=30km/h

now, average speed=2v1v2/v1+v2=40km/h✔️✔️

please mark it as brainlist if it helps ✨✨

Answer 2

✬ Average Speed = 40 km/h ✬

Explanation:

Given:

• A car covered half of distance with speed 60 km/h.
• The rest distance is covered with speed of 30 km/h.

To Find:

• What is the average speed of car ?

Formula to be used:

• Time = Distance/Speed
• Average Speed = Total distance/Total time

Solution: Let the total distance covered by car is 100. Therefore,

[ In first case ]

➛ Distance covered = Half of d

➛ Distance¹ = 100/2 = 50 km

➛ Speed of car = 60 km/h

∴ Time¹ take = 50/60 h

[ In second case ]

➨ Distance covered = Other half

➨ Distance² = 50 km

➨ Speed of car = 30 km/h

∴ Time² taken = 50/30 h

Now, Total distance covered by car is 100 km and total time taken by car is

➮ T¹ + T² = 50/60 + 50/30

➮ 50 + 100/60

➮ 150/60 h

Hence, Average Speed = Total distance/Total time

$\implies{\rm }$ 100 km / 150/60 h

$\implies{\rm }$ 100(60)/150 km/h

$\implies{\rm }$ 6000/150 km/h

$\implies{\rm }$ 40 km/h

Option (2) is correct.