Answer:
3503.72 seconds
819.96 seconds
Explanation:
=Velocity of river = 0.566 m/s
=Velocity of student = 1.17 m/s
Distance to travel = 1.57 km = 1570 m
So,
Time = Distance / Speed

Time taken by the student to complete the trip is 3503.72 seconds
In still water

The difference in time between moving water and still water is 3503.72-2683.76 = 819.96 seconds
A meandering stream I think is a tall
As Rene Descartes - french mathematician of Cartesian graphs - said "Cogito ergo sum". I think, therefore I am.
This can be adapted to I think therefore I am, I think ... as a "geeky joke".
A because it some type of friction