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A river is flowing at 3m//s . A boat can...

A river is flowing at `3m//s` . A boat can move at `5m//s` in still water. Boat starts from point `A`. Width of river is `120m`. Select the incorrect statement `:-`
.

A

Boat can cross the river in minimum time `24` sec .

B

Drift of the boat is zero if it starts at `127^(@)` from the direction of flow.

C

If boat is started perpendicular to the flow w.r.t. river then it will appear to move at `37^(@)` from direction of river flow for the ground observer.

D

If boat crosses the river the in minmim time, drift of boat will be `72 m`

Text Solution

Verified by Experts

The correct Answer is:
C
For minumum time, `v_(mr)` perpendicular to the river flow.

`theta cancel=37^(@)`
`[(tmin=(120)/(5)=24m//sec),("Drift"=24xx3=72m)]`
for drift to be zero `rArr` The resulant velocity must be towards `'B'`

`therefore127^(@)` from the river flow.
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