56
According to the theory of special relativity by Albert Einstein, mass and energy
can be interchanged. As per the theory, energy of a body is related to speed of light
and mass by following equation.
E mc
=
2
Where
E = total energy of possessed by object with mass m
c = speed of light = 3,00,000 km/s
Table 2.3 Common terms used in solid mechanics
Sl.
no. Terms
Description
1.
Intermolecular
force
Force exerted by molecules on each other in an object
2.
Elasticity
Property of a body due to which it regains its original configuration
after removing deforming forces
3.
Perfectly elastic
body
A body that returns to its original configuration completely and
immediately after removing deforming force from it
4.
Plasticity
Property of a body due to which it is unable to regain its original shape
or size even after removal of deforming force
5.
Stress
The ratio of internal force generated when a body is deformed in the
area on which this force acts; in equilibrium, internal force is equal to
external force in magnitude; in SI unit, stress is measured in N/m
2
6.
Normal stress
Normal stress is the stress generated when a force is applied
perpendicular to surface of a body; normal stress is of two types—
compressive stress and tensile stress
7.
Tangential stress Tangential stress is the stress generated when a force is applied parallel
to surface of a body
8.
Strain
It is the ratio of the alteration in size/shape to the original size/shape;
strain is a dimensionless number
9.
Longitudinal
strain
Ratio of alteration in length to initial length (Fig. 2.3)
10. Volumetric
strain
The change in volume divided by the original volume
11. Shear strain
Ratio of the length of deformation to perpendicular length in the plane
of the application of force (Fig. 2.4)
12. Elastic limit
The maximum stress to which the body can recover its original size and
shape on the elimination of the deforming force
13. Modulus of
elasticity
Ratio of stress to the corresponding strain within elastic limits; it is
constant within elastic limit as per Hooke’s law
2 Fundamentals of Physics for Environmental and Medical Professionals
According to the theory of special relativity by Albert Einstein, mass and energy
can be interchanged. As per the theory, energy of a body is related to speed of light
and mass by following equation.
E mc
=
2
Where
E = total energy of possessed by object with mass m
c = speed of light = 3,00,000 km/s
Table 2.3 Common terms used in solid mechanics
Sl.
no. Terms
Description
1.
Intermolecular
force
Force exerted by molecules on each other in an object
2.
Elasticity
Property of a body due to which it regains its original configuration
after removing deforming forces
3.
Perfectly elastic
body
A body that returns to its original configuration completely and
immediately after removing deforming force from it
4.
Plasticity
Property of a body due to which it is unable to regain its original shape
or size even after removal of deforming force
5.
Stress
The ratio of internal force generated when a body is deformed in the
area on which this force acts; in equilibrium, internal force is equal to
external force in magnitude; in SI unit, stress is measured in N/m
2
6.
Normal stress
Normal stress is the stress generated when a force is applied
perpendicular to surface of a body; normal stress is of two types—
compressive stress and tensile stress
7.
Tangential stress Tangential stress is the stress generated when a force is applied parallel
to surface of a body
8.
Strain
It is the ratio of the alteration in size/shape to the original size/shape;
strain is a dimensionless number
9.
Longitudinal
strain
Ratio of alteration in length to initial length (Fig. 2.3)
10. Volumetric
strain
The change in volume divided by the original volume
11. Shear strain
Ratio of the length of deformation to perpendicular length in the plane
of the application of force (Fig. 2.4)
12. Elastic limit
The maximum stress to which the body can recover its original size and
shape on the elimination of the deforming force
13. Modulus of
elasticity
Ratio of stress to the corresponding strain within elastic limits; it is
constant within elastic limit as per Hooke’s law
2 Fundamentals of Physics for Environmental and Medical Professionals