A river is flowing with speed 4 km/hr. A person is having speed 4 km/hr in still
water. Person wants to reach at point B (directly) opposite end of the river. Then
B
4km/hr
A
He should swim making an angle 45° with line AB
Person will never reach at point B
Person has to have speed less than 4 km/hr wrt river to reach at B
Speed of person w.rt. river is 4 v2 km/hr
Answers
Answer:
Bro your answer
Step-by-step explanation:
A swimmer swims in still water at a speed =5 km/hr. He enters a 200 m wide river, having river flow speed =4 km/hr at point A and proceeds to swim at an angle of 127
∘
with the river flow direction. Another point B is located directly across A on the other side. The swimmer lands on the other bank at a point C, from which he walks the distance CB with a speed =3 km/hr. The total time in which he reaches from A to B is
HARD
Share
Study later
ANSWER
V
S
=V
SR
+V
R
V
S
=(V
R
−V
SR
Sin30
∘
).(0.05)
Displacement along x−axis=
d=(V
R
−V
S
RSin37
∘
).(0.05)
=[4−5(
5
3
)].(0.05)
=0.05km
=50m
journey time (only while swimming)
=
V
VR
cos37
∘
200×10
−3
= 0.05hr
total time =
3km/hr
50×10
−3
km
+0.05hr
=
3
0.05
+0.05=
3
0.20
=0.0666hr=4mins
solution
Answer ByavatarToppr
SHARE
ASK
Get Instant Solutions, 24x7
No Signup required
girl
More Questions by difficulty
EASY
MEDIUM
HARD
Prev Question
Next Question
Related Questions to study
A man can swim with a speed of 4.0 km/hr in still water. How long does he take to cross a river 1.0 km wide, if the river flows steadily at 3.0 km/hr and he makes his strokes normal to the river current? How far down the river does he go, when he reaches the other bank?
Study later
View Answer
A man wishes to swim across a river 0.5 km wide. If he can swim at the rate of 2 km/h in still water and the river flows at the rate of 1 km/h. The angle (w.r.t the flow of the river) along which he should swim so as to reach a point exactly opposite his starting point, will be
Study later
View Answer
VIEW MORE
Revise with Concepts
Relative Velocity - 2D - Problem L2
EXAMPLE
DEFINITIONS
FORMULAES
20,000+
Learning videos
8,000+
Fun stories
10,000+
Fundamental concepts
8,00,000+
Homework Questions
Quick summary with Stories
Problem on relative motion L2
3 mins read