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A river flows with a speed of 3km/h in still water. A man who can swim with a speed of 5km/h wishes to reach a point on the other bank just opposite to the starting point. In which direction should he put his strokes and how long will he take to cross the river of width 1.2km? Please try to provide a diagram and step by step explanation.

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Answer:

Step-by-step explanation:

Let the angle required be θ with direction opposite to current .

cos θ = 3 / 5

θ = 53° .

Resultant velocity towards the opposite side

= √ ( 5 ² - 3²)

= 4 km /h

distance covered = 1.2 km

time taken = 1.2 / 4 = .3 h

= 18 min .

A river flows with a speed of 3km/h in still water. A man who can swim with a speed-example-1
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