The boy ran the distance of 100 m in 20 seconds. The next 200 meters in 50 seconds.

The boy ran the distance of 100 m in 20 seconds. The next 200 meters in 50 seconds. Find the speed of each distance and the average speed of the entire road.

Initial data: S1 (length of the first distance) = 100 m; t1 (time of passing the first distance) = 20 s; S2 (length of the second course) = 200 m; t2 (time of passing the second distance) = 50 s.

1) The boy’s speed at the first distance: V1 = S1 / t1 = 100/20 = 5 m / s.

2) The boy’s speed at the second distance: V2 = S2 / t2 = 200/50 = 4 m / s.

3) Average speed of the boy at two distances: Vav. = (S1 + S2) / (t1 + t2) = (100 + 200) / (20 + 50) = 4.29 m / s.