Question

A swimmer crosses a flowing stream of width d to and fro in time T1 . The time taken to cover the same distance up and down the stream is T2 then the time the swimmer would take to swim a distance 2d still water is

Answer 1

Answer:

t^2,1 = t3 + t3

Explanation:

Let v be the river velocity and u the velocity of swimmer in still water. Then

t1=2(Wu2−v2−−−−−−√)

t2=Wu+v+Wu−v=2uWu2−v2andt3=2Wu

Now we can see that t21=t2t3