A boat crosses a river with a velocity of . If the resulting velocity of boat is , then the velocity of river water is:
Step 1: Given data and drawing the vector diagram of the given situation
Velocity of boat
Resultant velocity of boat
Let velocity of river
The vector diagram is given below:
Step 2: Calculating the velocity of river
By observing the vector diagram we can write
Now squaring on both sides we get
Therefore the velocity of river water is equal to .
Hence, option(B) is the correct answer.