Arnav, while driving to school, computes his average speed for the trip to be 40 km/h on his return trip along the same route, the average speed is 60 km/h. Find the average speed for the entire trip.
Answers
Arnav, while driving to school, computes his average speed for the trip to be 40 km/hr on his return trip along the same route, the average speed is 60 km/hr.
We have to find the average speed of the entire trip.
Let us assume that the distance covered by the Arnav is x km.
Average speed is defined as the ratio of total distance covered with respect to total time taken.
Now,
Total distance covered = Distance covered in (first half + second half)
= x + x = 2x km
Time = Distance/Speed
t1 = x/40 hr and t2 = x/60 hr
Total time taken = t1 + t2
= x/40 + x/60
= x/20(1/2 + 1/3)
= x/20(5/6)
= x/24 hr
Average speed = (Total distance covered)/(Total time taken)
Substitute the values in the above formula,
= 2x(x/24)
= 48 km/hr
Therefore, the average for the entire trip is 48 km/hr.
Answer:
average speed of Arnav's trip =Vav=
2v1v2
____
v1+v2
= 2×40×60
________ = 4800
____. = 48km/h
40+60
100