The document presents information about elasticity from a physics course. It discusses how elasticity is the property of materials to return to their original shape after being deformed by an external force. Within the elastic limit, stress is directly proportional to strain, following Hooke's law. There are various elastic moduli that measure a material's resistance to deformation, such as Young's modulus, shear modulus, and bulk modulus. The elastic limit is the maximum stress a material can handle before becoming permanently deformed.

1. PRESENTATION ON
“ Elasticity “
COURSE TITLE : Physics I
COURSE CODE : PHY 101
Submitted To
MS. AFSANA MIMI RAKA
Lecturer
Department of EEE
Green University Of Bangladesh
Submitted By
Rashid Abid Moon ,
ID: 201003018
Department of Textile Engineering
Green University Of Bangladesh

2. PRESENTATION ON
“ Elasticity “

3. • About Elasticity
• Properties of Elasticity
• Elastic Limit & Plasticity
• Hook’s Law
• Modulus of Elasticity
• Young , Bulk & Shear Modulus
• Stress and Strain
• Elasticity Vs Plasticity
• Elastic Limit

4. • Property of a body that resists the trend of
changing the shape or volume or both due
to the action of the applied force on the
body and regains its original shape or
volume when the applied force is
withdrawn is called elasticity.
• The ability of an object or material to
resume its normal shape after being
stretched or compressed is call elasticity

5. In physics elasticity is a physical proporty of materials which
return to their orginal shape after they are deformed .
When an elastric material is deformed due to an extemal force ,
it experiences internal forces that oppose the deeformation and
restore it to its orginal state if the extermal force is removed
Therre are various elastic moduli , such as young's modulus the
shera modulus and bulk modulus , all of which are measures of
the inherent stiffness of a material as a resistance to
deformation under an applied load .
The elasticity of material is described by a stress - strain curve ,
Which shows the relation between stress .

6. It is the upper limit of deforming force up to which, if the deforming
force is removed, the body regains its original shape completely. If
the deforming force is increased beyond its elastic limit, the body
loses its elasticity.
Elastic Limit
Plasticity
The property of remaining deformed after removing the deforming
force or external force is termed as plasticity of the material.
Plastic Body
The body which remains with the deformed shape after the removal
of deforming force, is known as plastic body.

7. “Within the elastic limit the
stress is directly proportional to the strain”.
Within the elastic limit,
Where K is proportionality constant and
is called as modulus of
elasticity.
HOOK’S LAW
Mathematical form of hook’s law
LAW Of Elasticity
OR

8. The ratio of stress to the strain within the elastic limit, is called as
modulus of elasticity. Its value depends on the nature of
material. It is also called as the coefficient of elasticity of the
material. The unit and dimension of stress are the unit and
dimension of the modulus of elasticity.
MODULUS OF ELASTICITY
Young
modulus
Bulk
modulus
Shear
modulus

9. Young
modulus
Shear
modulus
Bulk
modulus
Within elastic limit , the ration of the
longitudinal stress to the longgitudinal
strain of a body is a constant . This
constant is called the Young Modules
of the material of the body .
Within elastic limit , the ration of the
volume stress to the volume strain of
a body is a constant . This constant is
called the Bulk Modules of the
material of the body .
Within elastic limit , the ration of the
shear stress to the shear strain of a
body is a constant . This constant is
called the Rigidity/Shear Modules of
the material of the body .

10. Stress refers to the cause of a deformation
Stress and Strain
strain refers to the effect of the deformation.
The downward force F causes
the displacement x.
Thus, the stress is the force;
the strain is the elongation.

11. For wires, rods, and bars,
there is a longitudinal
stress F/A that produces a
change in length per unit
length. In such cases

12. When the deforming force acting
tangentially to the surface of a
body changes the shape of the
body, then this stress is called
as tangentially stress or
shearing stress.

13. A compressive stress
occurs when equal
and opposite forces
are directed toward
each other.
A tensile stress occurs
when equal and
oppositeforces are
directed away from
each other