Question

A river has a steady speed of 0.480 m/s. a student swims upstream a distance of 1.00 km and swims back to the starting point. (a) if the student can swim at a speed of 1.40 m/s in still water, how long does the trip take?

Answer 1

Steady speed of river = 0.480 m/s

Swimming speed of student in still water = 1.40 m/s

When the student is swimming upstream the velocity he is going up = 1.40-0.48= 0.92 m/s

When the student is swimming downstream the velocity he is going down = 1.40+0.48= 1.88 m/s

Time taken to travel upstream =
`(1000)/(0.92) =1087 seconds = 18.12 minutes`

Time taken to travel downstream =
`(1000)/(1.88) =592 seconds = 8.87 minutes`

Total time taken = 18.12+8.87 = 26.99 minutes