Question

a boatman can row with a speed of 10km/h in still water. if the river flows steadily at 5 km/h, in which direction should the boatman row in order to reach a point on the other bank directly opposite opposite to the point from where he started? the width of the river is 2 km

Answer 1

Answer:

Assume that the boatman has to go in a direction making an angle θ with the line joining starting and finishing points

 

The resultant velocity should be along OA. Riverflow is in the direction shown i.e.  from left to right.

From the triangle shown, sin θ = (5 km/hr) / (10 km/hr) = 0.5.

Hence the direction, i.e. angle θ = 30 deg.

Explanation:

Answer 2

Heya Dost.. ❤

Thus the Boatman must row the boat in a direction at an angle of 120° with the direction of river flow. The direction doest not depend on width of the river.

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