Volume of Sphere and Hemisphere(Sphere With Examples) Video Lecture - Class 9

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we'll see how to find the volume of a
sphere sphere B M already told is again
three-dimensional figure it's perfectly
geometrical perfectly circular perfectly
down it looks like a ball
what do you think of a sphere the set of
all points that at the same distance R
from given point of the center in the
three-dimensional space it is not a
polygon
it's not we can do on the phone also so
first we do is calculate the radius of
the sphere what we found the radius of
the sphere will take one cylinder or
we'll take it even slightly and fill it
with water so once it can be of any
shape
let make sure that you have some
structure here which can store water
because this to this tank and some water
will spill over it's done
so we dip this so once you do this if
you see some what was paid over and you
could see what layer now you know what
you know the radius of a slip now
calculate the volume of this one so
you'll hit some well okay you calculate
and also since um our calculate four by
three pie honey and you know observe
that these two banners are seen that
means the volume of sphere is 4 by 3 PI
R cube okay so what we did we took a
sphere form the radius person and took a
tank full of water and dip that sphere
in the tank and supported spin out
before the volume of water and before
had a volume of water exactly equal to 4
by 3 PI R so with that we concluded that
the volume of sphere is 4 by 3 PI R
similarly volume of a me sphere will be
half of us this 2 by 3 PI R cube so
different critical formulas whatever
sphere is 4 by 3 PI R cube volume of
sphere is 2 by 3 PI R cube you see the
units are you need to be a leader that
will be the unit of volume of sphere and
stick some new Magus to understand the
concept for that time the basic
numerical here we have to find the
volume of the sphere whose radius is 11
point 2 centimeter so volume is nothing
but 4 by 3 PI R T we know the radius is
the rather the formula goes by 3 by 7
and be in centimeter you you solve this
we get finally 87.3 2 that is the volume
of the sphere it is a shotput
is a metallic sphere of radius o density
of the middle is 7.2 find the mass of
the truck it easy so we know that
density is equal to mass by 1 so mass
will be density into one density is
given into first find the volume of the
sphere so volume of the sphere we know
that
it's pretty easy by 3 PI R cube here in
just put the values the answer 7 so you
saw this you can almost 493 centimeter
that is the volume of the sphere
hey so mass can we go to what density
into volume we just don't
yes T's 17.8% it into column is 493
centimeter two centimeter two centimeter
will cancel if you multiply two eight
three three four five five gram if you
want to convert this into crazy it is
almost 3.8 5kg type it is he here you
define mass masses nothing my density is
room to volume density was given it was
for volume and multiply that with the
given density reporter are your mass
heavy spherical ball radius three point
five centimeter what would be the volume
of water to contain it easy
TV volume to everybody happy honest
event is put the values 2 by 3 by 7 is 3
point 5 Q it will be in st. with them
you saw this you get that is the volume
of water it can the diameter of the moon
is approximately 1 foot diameter of the
earth right what is the fractional
volume of the earth both are spherical
right diameter is 1 foot it is lots of
even food so radius of Moon is 1/4 of
radius of Earth all right there's a
fraction of volume over to the volume of
moon so we just find volume of Earth by
okay with this I can see that radius of
Earth is 43 is 4 so let's find that
falling apart is what 4 by 3 PI R
because earth is spherical volume of
Moon is 4 by 3 PI gets cancelled means
cancer so what you are left with so what
is the iron is 4 times R cubed so this
gets cancelled 4 into 4 to the power 3
is 64 so volume of Earth by volume of
Moon is 64
hey all I can see that mu is equal to 1
by 64 you do it easy so pretty easy
question how many litres of milk and a
hemispherical power of diameter and 25
centimeters the radius will be 10 point
5 by 2 centimeter so what is the volume
of this so this is nothing but 2 by 3 PI
R cube is a spherical put the values 2
by 3 into 27 we solve it you get 303
centimeter you nothing but 0.3 is 0-3
meters so the only difference in this
question extra parties question is
they're asking for answers to be leaders
so we know that 1000 centimeter 2 is 1
liter so with that we could actually the
word 303 centimeter you do liters at
this point 3 0 3 liters again
hemispherical time is made up of iron
sheet 1 centimeter thick the inner
radius is 1 meter find the polymer I
then used to make this so there is some
thickness here and this is a centimeter
this is meter so confusing for me so
what I can do is I can convert this a 2
say dat - Hey - the email radius is what
100 centimeter the hotel it is is 100
101 City so with that volume of Island
you should be 1 2 by 3 PI R 2 minus R 1
T if you take volume of the bigger blue
with the smaller sorry because very
image here and subtract to the volume
smaller space here you get the volume of
the material used it is my metier lasers
so put the values here 2 pi 3 into 20 by
7 this is the on side so you saw this 8
6 3 4 3-0 meter cube and are they no
they're not looking in any unit so this
is all-sufficient same 340 0 centimeters
cubed and so if you want you can convert
centimeter view by dividing by these
very same people who is equal to 1 meter
so you divide by this number so you get
0
six okay
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