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**A body of volume 100cm3 weighs 1 kgf in air. Find: (i) its weight in water and (ii) its relative density.**

Answer:

Given:

Volume of the body = 100cm3

Weight of the body in the air, W1= 1kgf or 1000gf

Let Weight of the body in water be W2

We know that R.D of water is 1 and that of a solid is 10

(i) To find the weight of the body in water

\text { Relative density of the body }=\frac{w_{1}}{W_{1}-W_{2}} x \text { relative density of water }

\begin{array}{l} 10=\frac{1000}{1000-W_{2}} \times 1 \\ 10\left(1000-W_{2}\right)=1000 \end{array}

W2 = 1000 – 100 = 900 gf

(ii) To find the relative density of the body

Density of the body = mass/volume

= 1000/100 = 10gf

Relative density is equivalent to density in C.G.S. with no unit, hence R.D. of the body is 10.

"hello everyone welcome to lido this is
priya
and here we have a question about the
salt
let us look into the question a body of
volume 100 cubic centimeters
weighs 1 kgf in air
find its weight in water and
its relative density so first
we try to solve the first one its weight
in water so what we know from this given
question
is the volume of object
volume of the object
which is 100
cubic centimeters
and we know the weight of the object
in the air weight of the
object in air
which is one k g
f and let's
take the weight of the object in water
as w2 and this
is w1 and let
let us assume
let us assume weight
of the body in
weight of the body in water
as w2 and
as we know the relative density
of the object
in what um as we know that the
relative density of water is
1 and
that of a solid is 10
so to find out the weight of the object
in water
the relative density of the body
relative density of
body equal to
w 1 by w
1 minus w 2
so by substituting this 10
equal to 1000
by 1000
minus w2
into 1 which
comes
10 equal to 1000
by thousand
minus w two into one
that implies ten into
thousand minus
w2 equal to
1000 then
w2 equal to
thousand minus
100 which is 900
k g f
which is a 1000 gf
so weight in water so the object weight
in water is
900 gf now
let us try to find out its relative
density
as we know the relative density
equal to
density
without units
then first we need to find out the
density
so we have a formula density as mass per
volume so what's the mass we have
mass is 1000 and volume is 10
so the density is 10
g f so the relative density
has no units so the relative density of
the object will be
temp hope you understand this video if
you like my video please subscribe to
our leader channel and if you have any
doubts you can keep a message in comment
box
thank you"

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