1. Tardigrade
  2. Question
  3. Physics
  4. A man wants to swim across a river of width 200 m along the shortest path. If the speed of river stream is 3 km h- 1 and speed of swimmer in still water is 5 km h- 1 , then the time of crossing the river is

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. A man wants to swim across a river of width $200 \, m$ along the shortest path. If the speed of river stream is $3 \, km \, h^{- 1}$ and speed of swimmer in still water is $5 \, km \, h^{- 1}$ , then the time of crossing the river is

NTA AbhyasNTA Abhyas 2020Motion in a Plane

Solution:

Speed of swimmer in still water = Speed of swimmer with respect to river.
Solution
$v_{\bot}=\sqrt{5^{2} - 3^{2}}=4kmh^{- 1}$
$\therefore \, \, \, t=\frac{0.2}{4}\times 40min=3min$