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A boat which has a speed of 5kmh^(-1) in...

A boat which has a speed of `5kmh^(-1)` in still water crosses a river of width 1 km along the shortest possible path in 15 min. The velocity of the river water in `km h^(-1)` is

A

1

B

2

C

3

D

`sqrt(41)`

Text Solution

Verified by Experts

The correct Answer is:
C

`s=ut`
`1=v_(BR) cos theta t`
`1=5 cos theta 1/4`
`cos theta=4/5 rArr theta=37^(@)`
`v_(R)=v_(BR) sin 37^(@)=5xx3/5=3 km//hr`
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