h.
1
ec
M
Arulmigu Meenakshi Amman college of Engineering
f./
Vadamavandal-604410.
ro
,P
Prepared by,
hy
at
V.Umapathy,
ap
m
Prof./Mech.
U
V.
Imortant Questions and Answers
PH25C05 –Applied Physics (ME)-II
Syllabus
1. Rigid Body Dynamics: Centre of mass – Moment of inertia (circular disc, solid cylinder,
hollow cylinder, solid sphere, hollow sphere), Gear, shaft, gyroscope.
2. Thermal Physics: Thermal conductivity –Transient plane source method, Transient Line
Source method- Forbe’s method - conduction through compound media, Laws of
Thermodynamics .
3. Phase Transitions: Solid solutions - single component system, binary phase diagrams -
iron-carbon equilibrium diagram, T-T-T-diagram - heat treatment of steels – hardening
techniques
4. Functional Materials: Ceramics – Composites, Fiber Reinforced Plastics, Metallic Glasses,
LED Characteristics
S.No Description
.
Unit-I
Rigid Body Dynamics
Introduction
1. Introduction
Study of objects with fixed shape & size
Motion under external forces & torques
2. Centre of Mass (COM)
Point where mass is concentrated
Motion described by COM
COM for common shapes
, h.
2
ec
M
f./
ro
,P
hy
at
ap
m
U
V.
3. Moment of Inertia (I)
Resistance to rotational motion
Depends on mass distribution
Moments of Inertia
Circular Disc- I = 1/2 MR² (about central axis)
Solid Cylinde- I = 1/2 MR² (about central axis)
Hollow Cylinder- I = MR² (about central axis)
Solid Sphere- I = 2/5 MR² (about diameter)
Hollow Sphere- I = 2/3 MR² (about diameter)
4. Applications
Gears- Transmit rotational motion
Shafts- Transmit torque
Gyroscopes- Maintain orientation
Basic Concepts
1. Centre of Mass (COM)
Point where mass acts
Like a balancing point
Why COM matters
Simplifies motion analysis
External forces act on COM
2. Moment of Inertia (I)
Resistance to rotation
Depends on:
, h.
3
ec
M
- Mass
f./
- Distribution from axis
ro
Common I values
,P
Circular Disc- I = 1/2 MR² (about central axis)
hy
Solid Cylinde- I = 1/2 MR² (about central axis)
at
ap
Hollow Cylinder- I = MR² (about central axis)
m
Solid Sphere- I = 2/5 MR² (about diameter)
U
Hollow Sphere- I = 2/3 MR² (about diameter)
V.
3. Applications
Gears: transmit rotation
Shafts: transmit torque
Gyroscopes: maintain orientation
Two Marks QA
1. What is Centre of Mass?
Point where entire mass acts
2. COM of uniform circular disc?
At center
3. Write the formula of Moment of Inertia of solid cylinder?
I = 1/2 MR² (about central axis)
4. Write the formula of hollow sphere?
I = 2/3 MR² (about diameter)
5. Write the Use of gears?
Transmit rotational motion
6. State the Application of gyroscope?
Maintain orientation
7. I of circular disc?
I = 1/2 MR² (about central axis)
8. COM of hollow sphere?
, h.
4
ec
M
At center
f./
13 and 15 Marks QA
ro
1. Derive moment of inertia for a solid cylinder about its axis.
,P
hy
at
ap
m
U
V.
2. Explain the working principle of a gyroscope.
Key Concept
1
ec
M
Arulmigu Meenakshi Amman college of Engineering
f./
Vadamavandal-604410.
ro
,P
Prepared by,
hy
at
V.Umapathy,
ap
m
Prof./Mech.
U
V.
Imortant Questions and Answers
PH25C05 –Applied Physics (ME)-II
Syllabus
1. Rigid Body Dynamics: Centre of mass – Moment of inertia (circular disc, solid cylinder,
hollow cylinder, solid sphere, hollow sphere), Gear, shaft, gyroscope.
2. Thermal Physics: Thermal conductivity –Transient plane source method, Transient Line
Source method- Forbe’s method - conduction through compound media, Laws of
Thermodynamics .
3. Phase Transitions: Solid solutions - single component system, binary phase diagrams -
iron-carbon equilibrium diagram, T-T-T-diagram - heat treatment of steels – hardening
techniques
4. Functional Materials: Ceramics – Composites, Fiber Reinforced Plastics, Metallic Glasses,
LED Characteristics
S.No Description
.
Unit-I
Rigid Body Dynamics
Introduction
1. Introduction
Study of objects with fixed shape & size
Motion under external forces & torques
2. Centre of Mass (COM)
Point where mass is concentrated
Motion described by COM
COM for common shapes
, h.
2
ec
M
f./
ro
,P
hy
at
ap
m
U
V.
3. Moment of Inertia (I)
Resistance to rotational motion
Depends on mass distribution
Moments of Inertia
Circular Disc- I = 1/2 MR² (about central axis)
Solid Cylinde- I = 1/2 MR² (about central axis)
Hollow Cylinder- I = MR² (about central axis)
Solid Sphere- I = 2/5 MR² (about diameter)
Hollow Sphere- I = 2/3 MR² (about diameter)
4. Applications
Gears- Transmit rotational motion
Shafts- Transmit torque
Gyroscopes- Maintain orientation
Basic Concepts
1. Centre of Mass (COM)
Point where mass acts
Like a balancing point
Why COM matters
Simplifies motion analysis
External forces act on COM
2. Moment of Inertia (I)
Resistance to rotation
Depends on:
, h.
3
ec
M
- Mass
f./
- Distribution from axis
ro
Common I values
,P
Circular Disc- I = 1/2 MR² (about central axis)
hy
Solid Cylinde- I = 1/2 MR² (about central axis)
at
ap
Hollow Cylinder- I = MR² (about central axis)
m
Solid Sphere- I = 2/5 MR² (about diameter)
U
Hollow Sphere- I = 2/3 MR² (about diameter)
V.
3. Applications
Gears: transmit rotation
Shafts: transmit torque
Gyroscopes: maintain orientation
Two Marks QA
1. What is Centre of Mass?
Point where entire mass acts
2. COM of uniform circular disc?
At center
3. Write the formula of Moment of Inertia of solid cylinder?
I = 1/2 MR² (about central axis)
4. Write the formula of hollow sphere?
I = 2/3 MR² (about diameter)
5. Write the Use of gears?
Transmit rotational motion
6. State the Application of gyroscope?
Maintain orientation
7. I of circular disc?
I = 1/2 MR² (about central axis)
8. COM of hollow sphere?
, h.
4
ec
M
At center
f./
13 and 15 Marks QA
ro
1. Derive moment of inertia for a solid cylinder about its axis.
,P
hy
at
ap
m
U
V.
2. Explain the working principle of a gyroscope.
Key Concept
