A man travels first 160km at 64 km/hr and the next 160km at 80km/hr . Find his average speed?
Answers
Step-by-step explanation:
A car travels first 160 km at 64 km/hr and the next 160 km at 80 km/hr.
Furst we will calculate the time taken in both the journey
We know Distance = speed × time
Time = distance/speed
If a car travels 160 km of distance with a speed of 64 km/h
Distance = 160 km
Speed= 64 km/hour
Time taken in travel first half of the distance = 160 km/64 km per hr. = 5/2 hrs. = 2.5 hrs
The car cover next 160 km distance with a speed of 80 km/h.
Distance = 160 km.
Speed = 80 km/hour
Tine taken to cover second half of the distance = 160 km/80 km per hr = 2 hours
What is the average speed for the first 320 km of the tour?
Total time taken by car to cover 320 km distance = 2.5 hrs + 2 = 4.5 hrs.
Average speed of car = Total distance/total time
Average speed of car = 320 km /4.5 hour
320 / 4.5
= 3200/45
= 640/9
= 71.11 km/hr
Average speed of car = 71.11 km/hour
Answer: the average speed of the car was 71.11 km / hour