Question

N crosses a river of width 400 m flowing at 40 m/s in minimum time. if velocity of man in still water is 50 m/s then the displacement of man while he reaches the opposite bank of the river is
choose answer:

Answer 1

Here is your answer:

Explanation:

According to the given data:

Width of river = 400 m

Swimming speed = 50 m/s

Solution:

Time to cross the river = distance / speed = 400/10 = 40 s  

Horizontal displacement due to river speed = speed×time = 40×2 = 80 m

So the  displacement while reaching the opposite bank of the river is 80 m