NEET Exam > NEET Questions > Two discs are rotating about their axes, norm...
Start Learning for Free
Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]
- a)40
- b)60
- c)100
- d)120
Correct answer is option 'C'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
Two discs are rotating about their axes, normal to the discs and passi...
Given: m1 = 2 kg m2 = 4 kg
r1 = 0.2 m r2 = 0.1 m
w1 = 50 rad s–1 w2 = 200 rad s–1
As, I1W1 = I2W2 = Constant
By putting the value of m1, m2, r1, r2 and solving we get = 100 rad s–1
Most Upvoted Answer
Two discs are rotating about their axes, normal to the discs and passi...
Free Test
| FREE | Start Free Test |
Community Answer
Two discs are rotating about their axes, normal to the discs and passi...
Understanding the Problem
When two discs are brought into contact, they may exchange angular momentum. The principle of conservation of angular momentum states that the total angular momentum before the contact must equal the total angular momentum after contact, assuming no external torques are acting on the system.
Calculating Initial Angular Momentum
- Disc D1:
- Mass (m1) = 2 kg
- Radius (r1) = 0.2 m
- Angular velocity (ω1) = 50 rad/s
- Moment of inertia (I1) = 0.5 * m1 * r1^2 = 0.5 * 2 * (0.2^2) = 0.04 kg m²
- Angular momentum (L1) = I1 * ω1 = 0.04 * 50 = 2 kg m²/s
- Disc D2:
- Mass (m2) = 4 kg
- Radius (r2) = 0.1 m
- Angular velocity (ω2) = 200 rad/s
- Moment of inertia (I2) = 0.5 * m2 * r2^2 = 0.5 * 4 * (0.1^2) = 0.02 kg m²
- Angular momentum (L2) = I2 * ω2 = 0.02 * 200 = 4 kg m²/s
Total Initial Angular Momentum
- Total angular momentum before contact (L_total_initial) = L1 + L2 = 2 + 4 = 6 kg m²/s
Final Angular Velocity Calculation
After the discs come into contact, they rotate together with a common final angular velocity (ω_f). The total moment of inertia (I_total) after contact is:
- I_total = I1 + I2 = 0.04 + 0.02 = 0.06 kg m²
Using conservation of angular momentum:
- L_total_initial = I_total * ω_f
- 6 = 0.06 * ω_f
Solving for ω_f:
- ω_f = 6 / 0.06 = 100 rad/s
Conclusion
Thus, the final angular velocity of the system after the two discs come into contact is 100 rad/s, which corresponds to option 'C'.
When two discs are brought into contact, they may exchange angular momentum. The principle of conservation of angular momentum states that the total angular momentum before the contact must equal the total angular momentum after contact, assuming no external torques are acting on the system.
Calculating Initial Angular Momentum
- Disc D1:
- Mass (m1) = 2 kg
- Radius (r1) = 0.2 m
- Angular velocity (ω1) = 50 rad/s
- Moment of inertia (I1) = 0.5 * m1 * r1^2 = 0.5 * 2 * (0.2^2) = 0.04 kg m²
- Angular momentum (L1) = I1 * ω1 = 0.04 * 50 = 2 kg m²/s
- Disc D2:
- Mass (m2) = 4 kg
- Radius (r2) = 0.1 m
- Angular velocity (ω2) = 200 rad/s
- Moment of inertia (I2) = 0.5 * m2 * r2^2 = 0.5 * 4 * (0.1^2) = 0.02 kg m²
- Angular momentum (L2) = I2 * ω2 = 0.02 * 200 = 4 kg m²/s
Total Initial Angular Momentum
- Total angular momentum before contact (L_total_initial) = L1 + L2 = 2 + 4 = 6 kg m²/s
Final Angular Velocity Calculation
After the discs come into contact, they rotate together with a common final angular velocity (ω_f). The total moment of inertia (I_total) after contact is:
- I_total = I1 + I2 = 0.04 + 0.02 = 0.06 kg m²
Using conservation of angular momentum:
- L_total_initial = I_total * ω_f
- 6 = 0.06 * ω_f
Solving for ω_f:
- ω_f = 6 / 0.06 = 100 rad/s
Conclusion
Thus, the final angular velocity of the system after the two discs come into contact is 100 rad/s, which corresponds to option 'C'.
Attention NEET Students!
To make sure you are not studying endlessly, EduRev has designed NEET study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in NEET.
|
Explore Courses for NEET exam
|
|
Similar NEET Doubts
Top Courses for NEETView all
Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer?
Question Description
Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer?.
Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer?.
Solutions for Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for NEET.
Download more important topics, notes, lectures and mock test series for NEET Exam by signing up for free.
Here you can find the meaning of Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer?, a detailed solution for Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer? has been provided alongside types of Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D1 has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s–1. Disc D2 has 4kg mass, 0.1 m radius and initial angular velocity of 200 rad s–1. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad s–1) of the system is [NEET Kar. 2013]a)40b)60c)100d)120Correct answer is option 'C'. Can you explain this answer? tests, examples and also practice NEET tests.
|
|
Explore Courses for NEET exam
|
|
Suggested Free Tests
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!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup