Introduction - Mechanical Properties of Solids Video Lecture - Class 11

hello friends this video on mechanical
properties of solids is brought to you
by exam feel calm no more fear from exam
topics which we'll cover in this lesson
our introduction elastic behavior of
solids stress and strain Hookes law
stress-strain curve and elastic moduli
so let us start with the introduction of
solids and their mechanical properties
so what do we mean when we say that we
are going to talk about mechanical
properties of solids mechanical
properties of solids describe
characteristics such as their strength
and resistance to deformation that means
basically it talks about strength what
do you mean my strength strength is
nothing but the ability of an object to
withstand the applied stress like when
you give some stress on an object to
what extent it can be R that stress so
that is known as the strength of a
material when I talk of resistance to
deformation it means at certain times
you want to change the shape of some
objects so it talks about how does it
end that particular object is to the
change of shape because you concept at
certain times you see certain objects
which change their shapes very easily
for example if you think of something
like clay or mud it is very easy to
change their shape into your desired
form because their resistance to
deformation is less whereas if you think
of something like iron do you see that
it changes shape very easily no not at
all so an atom changes shape only when
it is heated to a very high temperature
because the resistance to deformation is
very high in case of iron so depending
upon different materials depending upon
their properties they have different
resistance to deformation so in this
chapter we will talk about such kind of
properties of solids so mechanical
properties there
use mechanical properties which can be
included in the list some of them are
elasticity how much elasticity a
substance possess for example when I
talk of elasticity the best thing you
can think of is a spring plasticity
which is just the reverse of elasticity
when I say elasticity I mean that you
stretch in for example you think of the
spring you stretch an object it changes
its shape once you leave the force it
regains its original shape or it comes
back to its original shape on the other
hand when I talk of plasticity it means
once you change the shape of the object
it never comes back to its original
shape even when the external forces
remove so those kind of substances are
known as plastic materials you also have
a property like ductility in ductility
when I say ductility it is something
like you can pull that material into
thin wires or into thin sheets for
example you can think of gold or silver
if you would have seen small thin plates
of hold or small thin chains or wires of
gold so that is because the material has
that property of being the pipe so not
only these there are various kinds of
properties which can be included inside
without mechanical properties of solids
in this chapter we will basically
concentrate on the elastic behavior of
soils so we will study about elasticity
so all that I explained you in brief
will quickly review it once again
elasticity it is the property to regain
original shape once the external force
is removed so elasticity the best
example I can think of is a spring next
is last ascetic property of permanent
deformation that means once changed it
will never come back to the original
shape for example a mud toy or a mud
when you change it to a different shape
it is not going to come back to its
original shape again unless and until
you again apply some force and efforts
and change ductility property of being
drawn into thin wires as I told you the
example which you can consider
we'll start off good you will also talk
of strength when we talk of mechanical
properties strength is nothing but the
ability to withstand applied stress
without failure that means when you try
to break something like you might you
would have seen several substances which
are very precise you apply a little bit
of pressure or force and it breaks down
whereas there are other categories of
materials who have which have got better
strength that is they do not they are
able to beer the applied stress for a
longer duration without failure so
strength is that property of the
material wherein the material can
withstand or beer the applied stress
without failure thank you please visit
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