Rob runs at a constant speed of 3.8 meters per second for one half hour. Then, he walks at a rate of 1.6 meters per second for one half hour. How far did Rob run and walk in 60 minutes?

9,720 meters, or 9.72 km

Step-by-step explanation:

Rob runs at a speed of V1 = 3.8 m/s for t1 = one half hour = 30 x 60 = 1,800 seconds.

=> the distance he runs S1 = V1 x t1 = 3.8 x 1,800 = 6,840 meters

He walks at V2 = 1.6 m/s for t2 = 1,800 seconds.

=> the distance he walks S2 = V2 x t2 = 1.6 x 1,800 = 2,880 meters

The total distance he runs and walks S = S 1 + S 2 = 6,840 + 2,880 = 9,720 meters