A boy moves with a speed of 8 km perfect hour in 3 hours and in next in 2 hours with speed of 6 km per hour find the average speed and moved
Answers
Answer:
average speed is 8km+6km/2 = 7km/per hour
Answer:
Average speed of the boy is 7.2 km/h.
Explanation:
♡In the first 3 hours.
Speed of the boy = 8km/h.
☆Let the distance covered by the boy in the first three hours be = D¹.
☆Let the time taken by the boy to cover the distance( D¹) in the first three hours be = T¹.
☆Let the speed of the boy in the first three hours be = S¹.
¤ Distance covered by the boy in the first three hours = D¹.
¤ Time taken by the boy to cover the D¹ distance in the first three hours = 3h.
¤ Speed of the boy in the first three hours = 8km/h.
● Speed of the boy in the first three hours.
S¹ = D¹/T¹.
8km/h = D¹/3h.
8 × 3 = D¹.
24km = D¹.
D¹ = 24km.
Distance (D¹) covered by the boy in the first three hours is 24km.
♡In the next two hours.
Speed of the boy = 6km/h.
☆Let the distance covered by the boy in the next two hours be = D².
☆Let the time taken by the boy to cover the distance(D²) in the next two hours be = T²
☆Let the speed of the boy in the next two hours be = S².
¤ Distance covered by the boy in the next two hours = D².
¤ Time taken by the boy to cover the distance(D²) in the next two hours = 2h.
¤ Speed of the boy in the next two hours = 6km/h.
● Speed of the boy in the next two hours.
S² = D²/T².
6km/h = D²/2h.
6 × 2 = D².
12km = D².
D² = 12km.
Distance(D²) covered by the boy in the next two hours is 12 km.
● Average speed of the boy = Total distance covered/Total time taken.
Average speed of the boy = D¹+D²/T¹+T².
Average speed of the boy = 24km+ 12km/3h + 2h.
Average speed of the boy = 36km/5h.
Average speed of the boy = 7.2km/h.