9514 1404 393
Answer:
27 minutes
Step-by-step explanation:
The relevant relations are ...
1 min = 60 s
1 km = 1000 m
time = distance/speed
__
time = (8.1 km)×(1000 m)/(1 km)/(5 m/s)×(1 min/(60 s))
= (8.1×1000)/(5×60) min = 27 min
It takes 27 minutes to cover 8.1 km at a speed of 5 m/s.