a car travels first one third with speed of 10km/hr,next one third distance with 20km/hr.What is the average of car for whole journey
Can't tell unless we get speed for last third.
2V1V2/V1+V2
2×10×20/10+20
400/30=10.333km/h
To find the average speed of the car for the entire journey, we need to know the total distance traveled and the total time taken.
Let's assume that the total distance traveled by the car is "D" kilometers.
Since the car travels the first one-third of the distance at a speed of 10 km/hr, it covers (1/3)D kilometers in that time. The time taken for this part of the journey can be calculated using the formula:
Time = Distance / Speed
Time = (1/3)D / 10 km/hr
Time = (1/30)D hours
Similarly, the car travels the next one-third of the distance at a speed of 20 km/hr. It covers another (1/3)D kilometers in that time. The time taken for this part of the journey can be calculated as:
Time = (1/3)D / 20 km/hr
Time = (1/60)D hours
Now, the total time taken for the entire journey is the sum of the times taken for each part:
Total Time = (1/30)D + (1/60)D
Total Time = (2/60)D + (1/60)D
Total Time = (3/60)D
Total Time = (1/20)D hours
Finally, we can calculate the average speed of the car for the entire journey using the formula:
Average Speed = Total Distance / Total Time
Average Speed = D / ((1/20)D)
Average Speed = 20 km/hr
Therefore, the average speed of the car for the entire journey is 20 km/hr.