a boy takes 4hr to travels from his home to school which is 9km away
and comes back to the same rood at speed of 5km per hr
Calculate the
average speed of the boy
plz step by step
Answers
Answer:
3.10kmh^-1
Explanation:
●Average Speed = Total distance travelled / Total time taken ,
•Total distance = 9km + 9km = 18km.
•Total time taken = 4hr + x . ( x is time taken to come back )
Now , on return journey , speed = 5kmhr^-1 and distance = 9km
time would be = 9km/5kmh^-1
thus , total time taken = [4 + (9/5)]hr = (29/5)hr
■Putting the values , = [18 / (29/5) ] kmh^-1= (18/3.8)kmh^-1 1
= 3.10kmh^-1 (approx.)
A boy takes 4 hours to travel from his home to school which is 9 km away.
Here, time i.e. t is 4 hours and distance i.e. d is 9 km.
Also, he returns back to his home (from school) using the same pathway, but with a speed of 5 km/hr.
We have to find the average speed of the boy.
Average speed is defined as the ratio of total distance covered with respect to total time taken.
Distance covered by the boy from home to school is 9 km. Similarly, from school to home he covered the distance of 9 km. Therefore, the total distance covered by the boy is 18 km.
From home to school:
Distance = Speed × Time
9 = s1 × 4
9/4 = s1
2.25 = s1
From school to home:
Distance = Speed × Time
9 = 5 × t1
9/5 = t1
1.8 = t1
Now,
Average speed = (Total distance covered)/(Total time taken)
Total distance covered = 18 km
Total time taken = t1 + t2 = (4 + 1.8)hr
Substitute the values in the above formula,
= 18/(4 + 1.8)
= 18/5.8
= 3.10 km/hr
Therefore, the average speed of the boy is 3.10 km/hr.