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A battalion of soldiers is ordered to sw...

A battalion of soldiers is ordered to swim across a river `500 m` wide. At what minimum rate should they swim perpendicular to river flow in order to avoid being washed away by the waterfall 300 m downstream. The speed of current being 3m/sec:

A

6 km/hr

B

3 km/hr

C

5 km/hr

D

4 km/hr

Text Solution

Verified by Experts

The correct Answer is:
C
Time to cross the river `t= (d) /(V_(p))` and drift .
` x= v_(R)xxt`
so ` x=v_(R ) (d)/(v_(P))`
`300 = 3 km // hr xx (500)/(v_(p))`
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