Elasticity is the property of an object to resume its normal shape after being deformed by a force. Stress is defined as the restoring force per unit area, while strain is the change in dimension per original unit of measurement. Tensile or longitudinal strain occurs when the strain is in the direction of the applied force. Bulk or volume strain is the fractional change in volume due to pressure changes, and shear strain is the ratio of lateral displacement to layer height. Young's modulus is the ratio of tensile stress to tensile strain and describes elasticity. Bulk modulus is similarly the ratio of bulk stress to bulk strain. Shear modulus is the ratio of shear stress to shear strain. Various experiments and equations are described to calculate

1. BASIC PHYSICS
TOPIC : ELASTCITY
Harshad P Patil
DMTC - I
2014140
@hplp99

2. Elasticity
 The property by virtue of which the body resists
the deforming forces into play internal restoring
forces and recover its original shape and size
when the deforming forces are removed is called
ELASTICITY.
 the ability of an object or material to resume its
normal shape after being stretched or
compressed; stretchiness.

3. Stress and Strain
 STRESS : The
restoring force
measured per unit
area of the surface
over which it acts is
called stress.
 STRAIN : It is define
as change in a
given dimension
per unit value of
original dimension
of a body.

4. TENSILE OR LONGITUDINAL
STRAIN
 When the strain in the body is in the direction of the force
producing it, the strain is called tensile or longitudinal strain
 It is measured as the ratio of change in length (l) to the
original length (l).

5. Bulk or Volume strain &
Shear strain
 Bulk or Volumes strain : it is measured by fractional
change in volume caused in a body by the change of
pressure acting on it.
 Shear strain : it is the ratio of lateral displacement of a
layer to the height of that layer above a fixed layer.

6. Young modulus of
elasticity, Y= m.g.L / r2
 Young’s moduls of elasticity is defined as the ratio of tensile
stress to tensile stain.
 Y=tensile stress/ tensile strain= F/A / l/L
 F = load applied
 A = area of cross section of the wire
 l =increase in length of wire
 L =original length of the wire.

7. Bulk modulus = K=f.v/A.dV.
 Bulk modulus of elasticity is defined as is ratio of
bulk stress to bulk strain.
 K= bulk stress/bulk strain = F/A / dV/V= N/mxm
 where,
 F=load applied
 A= area of cross correction
 dV= change in volume
 V=original volume

8. Shear moduls of Elasticity
n = F.h / A.x
 Shear moduls of elasticity is defined as the ratio of shears stress
to shears strain.
 n=shear stress/shear strain = F/A / x/h
 F= load applied
 A=area of cross section
 x= lateral displacement of a layer
 H= distance of that layer from bottom fix layer

9. Young modulus of elasticity using
Searle's apparatus

10. Strain energy store in per unit
volume of a wire

11. @hplp99
@hplp99