The minimum time required for a boat to cross a river is 30 min and the time required for the boat to cross the same river in the shortest possible path is 50 min. In both cases velocity of boat relative to still water is ‘v’ and velocity of water is ‘u’. Then uv is _____

Book Online Demo

Check Your IQ

Try Test

Courses

Dropper NEET Course Dropper JEE Course Class - 12 NEET Course Class - 12 JEE Course Class - 11 NEET Course Class - 11 JEE Course Class - 10 Foundation NEET Course Class - 10 Foundation JEE Course Class - 10 CBSE Course Class - 9 Foundation NEET Course Class - 9 Foundation JEE Course Class -9 CBSE Course Class - 8 CBSE Course Class - 7 CBSE Course Class - 6 CBSE Course

Offline Centres

The minimum time required for a boat to cross a river is 30 min and the time required for the boat to cross the same river in the shortest possible path is 50 min. In both cases velocity of boat relative to still water is ‘v’ and velocity of water is ‘u’. Then $\frac{u}{v}$ is ______

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

$\frac{5}{4}$

$\frac{2}{3}$

$\frac{4}{5}$

$\frac{3}{5}$

answer is C.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

$\begin{array}{l} \frac{d}{v} = t_{\min} = 30 ....... (1) \\ A l o n g t h e s h o r t e s t p o s s i b l e p a t h, \frac{d}{\sqrt{v^{2} - u^{2}}} = 50 ....... (2) \\ ∴ \frac{\sqrt{v^{2} - u^{2}}}{v} = \frac{30}{50} \Rightarrow \frac{u}{v} = \frac{4}{5} . \end{array}$