Question

A boat is rowed across a river (perpendicular to river flow) at the rate of 9 km/hr. The river flows at the
rate of 12 km/hr. The velocity of boat in km/hr is:
(A) 14
(B) 15
(C) 16
(D) 17
​

Answer 1

Answer:15

Explanation:hi

Since the boat is rowed perpendicular we can take 9kmh as the horizontal velocity of the boat .

Since the flow of river is perpendicular to the horizontal velocity of the boat we can take it as the vertical velocity

So we know that the angle between these two are 90...it is clear from the question

So

Resultant vector

Is

root off(9^2+12^2)

=15

Answer 2

hope it helps u a lot

12 square + 9 square = 225

AC square = 225

AC = 15

THANKS