Question 2
The two banks of a river are parallel horizontal straight lines. The current flows parallel to the banks from left to right with speed $u$. A ferry of constant speed $v$ relative to the water starts at $O$ on the lower bank, taken as the axis $Ox$, to carry a vehicle to the opposite bank.
(a) If the actual path of the ferry makes an angle $\alpha$ with $Ox$, what is its actual velocity $\vec V$? Discuss.
(b) What angle $\alpha$ minimizes the crossing time?
(a) If the actual path of the ferry makes an angle $\alpha$ with $Ox$, what is its actual velocity $\vec V$? Discuss.
(b) What angle $\alpha$ minimizes the crossing time?