Question

Two boats, A and B, move away from a buoy anchored at the middle of a river along the mutually perpendicular straight lines: the boat A along the river, and the boat B across the river. Having moved off an equal distance from the buoy the boats returned. Find the ratio of times of motion of boats τA/τB if the velocity of each boat with respect to water is η = 1.2 times greater than the stream velocity.

Answer 1

Let l be the distance covered by the boat  A along the river as well as by the boat B across the river. Let v₀ be the stream velocity and v' the velocity of each boat with respect to water. Therefore time is taken by the boat A in its journey