Question

A person aiming to reach exactly opposite point on the bank of a stream is swimming with a speed of 0.5 m/s at an angle of 120 degree with the direction of the flow of the water. The speed of water in the stream is
(1)0.25 m/s
(2)0.5 m/s
(3)1.0 m/s
(4)0.433 m/s

Answer 1

Answer on Question #60205-Physics-Mechanics-Relativity

A person aiming to reach exactly opposite point on the bank of a stream is swimming with a speed of 0.5 m/s at an angle of 120 degree with the direction of the flow of the water. The speed of water in the stream is

(1) $0.25 \mathrm{~m} / \mathrm{s}$

(2) $0.5 \mathrm{~m} / \mathrm{s}$

(3) $1.0 \mathrm{~m} / \mathrm{s}$

(4) $0.433 \mathrm{~m} / \mathrm{s}$

Solution

Here, $V_{r}$ is the velocity of the river w.r.t. ground, $V_{m}$ is the velocity of the man w.r.t. river, $V$ the velocity of the man w.r.t. ground.

$$\tan 9 0 = \frac {V _ {m} \sin 1 2 0}{V _ {r} + V _ {m} \cos 1 2 0}$$ $$V _ {r} = - V _ {m} \cos 1 2 0 = - (0. 5) (- 0. 5) = 0. 2 5 \frac {m}{s}$$

Answer: (1) $0.25 \, \text{m/s}$ .

https://www.AssignmentExpert.com