A person aiming to reach the exactly opposite point on the bank of a stream is swimming with a speed

Question

A person aiming to reach the exactly opposite point on the bank of a stream is swimming with a speed of $1.2 \mathrm{~m} / \mathrm{s}$ at an angle of $150^{\circ}$ with the direction of flow of water. The speed of water in the stream is

Professor PC Thomas Classes · Answer

(a) : Let $v_r$ be the velocity of river water. The angle with the perpendicular to the flow is $150^{\circ} - 90^{\circ} = 60^{\circ}$. \ To reach exactly opposite, the horizontal component of the swimmer's velocity must cancel the river's velocity. \ $	herefore v_r = 1.2 \sin 60^{\circ} = 1.2 	imes \frac{\sqrt{3}}{2} = 0.6\sqrt{3} \mathrm{~m} / \mathrm{s}$.