Question

A man is capable of swimming at $10\text{m/s}$ in still water. If he has to cross a river flowing at $5\text{m/s}$ and reach the opposite shore in the least possible time, how far along the river will he drift if distance between the two shore is $100\text{m}$.

• A. $5\text{m}$
• B. $10\text{m}$
• C. $50\text{m}$
• D. $100\text{m}$

Answer 1

The correct option is C $50\text{m}$


drift $=V_{rg}\times \frac{100}{V_{mr}}=5\times \frac{100}{10}=50\text{m}$.