Class 11 Exam > Class 11 Questions > A man can swim in still water at a speed of 6...
Start Learning for Free
A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours)
- a)2/27
- b)2/√27
- c)2/3
- d)2/√45
Correct answer is option 'B'. Can you explain this answer?
Most Upvoted Answer
A man can swim in still water at a speed of 6 kmph and he has to cross...
To reach the exact opposite end the parallel component of velocity would nullify the velocity of the river, hence we get 6.sin a = 3 , where a is the angle with perpendicular to river flow.
Thus we get sin a = ½ and cos a =√3/2
Thus the perpendicular component of velocity, 6.cos a = 3√3
Thus time taken is 2 / 3√3
Thus we get sin a = ½ and cos a =√3/2
Thus the perpendicular component of velocity, 6.cos a = 3√3
Thus time taken is 2 / 3√3
Free Test
FREE
| Start Free Test |
Community Answer
A man can swim in still water at a speed of 6 kmph and he has to cross...
Given data:
- Speed of man in still water = 6 kmph
- Speed of river flow = 3 kmph
- Width of the river = 2 km
To cross the river, the man needs to swim at an angle to the flow of the river. The resultant velocity (V) of the man will be the vector sum of his velocity in still water (6 kmph) and the velocity of the river flow (3 kmph). This can be found using the Pythagorean theorem as:
V = √(6^2 + 3^2) = √45 kmph
Now, we can use the formula:
Time taken to cross the river = Distance to be covered / Resultant velocity
The distance to be covered is the width of the river, which is 2 km. Substituting the values in the above formula, we get:
Time taken to cross the river = 2 / √45 hours
Rationalizing the denominator, we get:
Time taken to cross the river = 2√45 / 45 hours
Simplifying further, we get:
Time taken to cross the river = 2/27 hours
Therefore, the correct answer is option B) 2/27.
- Speed of man in still water = 6 kmph
- Speed of river flow = 3 kmph
- Width of the river = 2 km
To cross the river, the man needs to swim at an angle to the flow of the river. The resultant velocity (V) of the man will be the vector sum of his velocity in still water (6 kmph) and the velocity of the river flow (3 kmph). This can be found using the Pythagorean theorem as:
V = √(6^2 + 3^2) = √45 kmph
Now, we can use the formula:
Time taken to cross the river = Distance to be covered / Resultant velocity
The distance to be covered is the width of the river, which is 2 km. Substituting the values in the above formula, we get:
Time taken to cross the river = 2 / √45 hours
Rationalizing the denominator, we get:
Time taken to cross the river = 2√45 / 45 hours
Simplifying further, we get:
Time taken to cross the river = 2/27 hours
Therefore, the correct answer is option B) 2/27.
|
Explore Courses for Class 11 exam
|
|
Top Courses for Class 11View all
Question Description
A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours) a)2/27b)2/√27c)2/3d)2/√45Correct answer is option 'B'. Can you explain this answer? for Class 11 2025 is part of Class 11 preparation. The Question and answers have been prepared according to the Class 11 exam syllabus. Information about A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours) a)2/27b)2/√27c)2/3d)2/√45Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for Class 11 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours) a)2/27b)2/√27c)2/3d)2/√45Correct answer is option 'B'. Can you explain this answer?.
A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours) a)2/27b)2/√27c)2/3d)2/√45Correct answer is option 'B'. Can you explain this answer? for Class 11 2025 is part of Class 11 preparation. The Question and answers have been prepared according to the Class 11 exam syllabus. Information about A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours) a)2/27b)2/√27c)2/3d)2/√45Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for Class 11 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours) a)2/27b)2/√27c)2/3d)2/√45Correct answer is option 'B'. Can you explain this answer?.
Solutions for A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours) a)2/27b)2/√27c)2/3d)2/√45Correct answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 11.
Download more important topics, notes, lectures and mock test series for Class 11 Exam by signing up for free.
Here you can find the meaning of A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours) a)2/27b)2/√27c)2/3d)2/√45Correct answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours) a)2/27b)2/√27c)2/3d)2/√45Correct answer is option 'B'. Can you explain this answer?, a detailed solution for A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours) a)2/27b)2/√27c)2/3d)2/√45Correct answer is option 'B'. Can you explain this answer? has been provided alongside types of A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours) a)2/27b)2/√27c)2/3d)2/√45Correct answer is option 'B'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice A man can swim in still water at a speed of 6 kmph and he has to cross the river and reach just opposite point on the other bank. If the river is flowing at a speed of 3 kmph, and the width of the river is 2 km, the time taken to cross the river is (in hours) a)2/27b)2/√27c)2/3d)2/√45Correct answer is option 'B'. Can you explain this answer? tests, examples and also practice Class 11 tests.
|
|
Explore Courses for Class 11 exam
|
|
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up
within 7 days!
within 7 days!
Takes less than 10 seconds to signup