System of Particles and Rotational Motion Class 11 Case Study Questions Physics Chapter 6

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Hello students, we are providing case study questions for class 11 Physics. Case study questions are the new question format that is introduced in CBSE board. The resources for case study questions are very less. So, to help students we have created chapterwise case study questions for class 11 Physics. In this article, you will find case study questions for cbse class 11 Physics chapter 6 System of Particles and Rotational Motion.

Chapter	System of Particles and Rotational Motion
Type of Questions	Case Study Questions
Nature of Questions	Competency Based Questions
Board	CBSE
Class	11
Subject	Physics
Useful for	Class 11 Studying Students
Answers provided	Yes
Difficulty level	Mentioned
Important Link	Class 11 Physics Chapterwise Case Study

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Table of Contents

Case Study Questions on System of Particles and Rotational Motion

Case Study Question 1

Passage:
A uniform rod of length 2 m and mass 3 kg is placed on a smooth horizontal table. A small 1 kg mass is attached at one end of the rod. The system is free to move. A student is asked to find the centre of mass (COM) of this system from the heavier end of the rod and predict its motion if a force is applied at the COM.

Q1. What is the distance of the COM from the heavier end (3 kg side)?
(a) 1.0 m
(b) 1.25 m
(c) 0.75 m
(d) 1.5 m

Answer: (c) 0.75 m

Q2. If a horizontal force is applied at the COM, what type of motion will the system exhibit?
(a) Pure rotation
(b) Pure translation
(c) No motion
(d) Vibrational motion

Answer: (b) Pure translation
Explanation:
When force is applied at COM, there’s no torque, hence pure translational motion.

Q3. If the same force is applied at the free end of the rod instead of COM, what will happen?
(a) Only rotation
(b) Only translation
(c) Both rotation and translation
(d) The system will remain at rest

Answer: (c) Both rotation and translation
Explanation:
Force not at COM → produces torque + net force → both rotation and translation.

Case Study Question 2

Passage:
A uniform metre scale is suspended at its 50 cm mark. A mass of 80 g is placed at the 20 cm mark. Where should a mass of 120 g be placed on the other side to keep the scale horizontal?

Q1. What is the principle used to solve this problem?
(a) Law of inertia
(b) Law of conservation of energy
(c) Rotational equilibrium (Net torque = 0)
(d) Newton’s third law

Answer: (c) Rotational equilibrium
Explanation:
Balance requires net torque about pivot = 0

Q2. What is the torque due to 80 g mass about the pivot?
(a) 2400 g·cm
(b) 3000 g·cm
(c) 2000 g·cm
(d) 1000 g·cm

Answer: (a) 2400 g·cm

Q3. At what position should the 120 g mass be placed to balance the scale?
(a) 60 cm
(b) 70 cm
(c) 80 cm
(d) 90 cm

Answer: (b) 70 cm

Q4. What would happen if the 120 g mass is placed at 80 cm?
(a) System remains balanced
(b) Beam tilts to 120 g side
(c) Beam tilts to 80 g side
(d) No motion occurs

Answer: (b) Beam tilts to 120 g side
Explanation:
Greater torque on 120 g side → unbalanced → tilts right

Case Study Question 3

Passage:
A solid disc of mass 2 kg and radius 0.5 m rolls without slipping on a horizontal surface with a speed of 4 m/s. The student is asked to calculate its kinetic energy and rotational dynamics using principles of rolling motion.

Q1. What is the moment of inertia of the disc about its central axis?
(a) $\frac{1}{2} M R^2$
(b) $M R^2$
(c) $\frac{2}{3} M R^2$
(d) $\frac{1}{3} M R^2$

Answer: (a)
Explanation:
Moment of inertia of solid disc $=\frac{1}{2} M R^2$

Q2. What is the total kinetic energy of the disc?
(a) $\frac{1}{2} M v^2$
(b) $\frac{3}{4} M v^2$
(c) $\frac{1}{4} M v^2$
(d) $M v^2$

Answer: (b)
Explanation:

$$
K \cdot E_{\text {total }}=\frac{1}{2} M v^2+\frac{1}{2} I \omega^2=\frac{3}{4} M v^2
$$

Q3. What is the total kinetic energy of this rolling disc?
(a) 6 J
(b) 9 J
(c) 12 J
(d) 24 J

Answer: (d) 24 J

Q4. What is the angular velocity of the disc?
(a) $8 \mathrm{rad} / \mathrm{s}$
(b) $4 \mathrm{rad} / \mathrm{s}$
(c) $6 \mathrm{rad} / \mathrm{s}$
(d) $2 \mathrm{rad} / \mathrm{s}$

Answer: (b)
Explanation:
Rolling condition:

$$
v=R \omega \Rightarrow \omega=\frac{v}{R}=\frac{4}{0.5}=8 \mathrm{rad} / \mathrm{s}
$$

We hope the given case study questions for System of Particles and Rotational Motion Class 11 helps you in your learning.

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Topics from which case study questions may be asked

Centre of mass
Torque and angular momentum
Rotational motion
Moment of inertia

Rotational motion introduces the idea of moment of inertia, analogous to mass in linear motion.

For further practice on case study questions related to System of Particles and Rotational Motion Class 11 Physics, we recommend exploring the link given below.

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Frequently Asked Questions (FAQs) on System of Particles and Rotational Motion Case Study Questions

Q1: What are case study questions in System of Particles and Rotational Motion?

A1: Case study questions in System of Particles and Rotational Motion test your ability to apply concepts in real-life scenarios.

Q2: Are these questions asked in board exams?

A2: Yes, CBSE has started including case study/competency-based questions in final exams.

Q3: How should I prepare for case study questions?

A3: Focus on understanding concepts and practicing application-based problems.

Q4: Are answers provided for Class 11 Physics System of Particles and Rotational Motion case study questions?

A4: Yes, detailed answers are provided for all questions.

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