Question

A ship crosses a river aiming at the angle è to the left from the straight course. The speed of the ship with respect to water is v'. The width of the river is d and the water velocity is u to the right. What will be the side displacement h of the ship as it lands on the other shore?

Answer 1

Hmmmm. v' is respect to water....

That creates a really difficult problem, so I assume you don't mean that, but mean relative to still water.

Well, the velocity to the left is v'*sinTheta-u. I assume u is greater than the first term, so the velocity will be to the right.

Side displacement: figure the time across. d/v'costheta
then downstream distance d= velocity to right*time