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A boat travels from the south bank to the north bank of a river with a maximum speed of 8km/h. A river current flows from west to east with a speed of 4km/h. Find the angle with which the boat should be steered to arrive at a point opposite to the point of start.
(a) 60WofN
(b) 30WofN
(c) 60SofE
(d) 30SofE

Answer
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Hint: In order to answer this question, we have to calculate the angle with which the boat should be steered to arrive at a point opposite to the point of start, we will first draw a diagram respect to the given problem and then we will take sine angle to solve for it.

Complete step by step answer:
Velocity of the boat =8km/h
And, the velocity of the river from west to east =4km/h
So, according to the question:
seo images

In the above figure, the angle is θ .
So, as the angle with which the boat should be steered to arrive at a point opposite to the point of start is as:
Vbrsinθ=vsinθ=48=12
θ=30westofnorth .
Therefore, the angle with which the boat should be steered to arrive at a point opposite to the point of start is 30WofN .
Hence, the correct option is (b).

Note: As we know, the given question is related to the river boat topic, so to solve river boat problems, we need to understand two concepts: The speed of a boat relative to the water is equal to the speed of the boat in still water.