Determination of Density of Solid, Physics, Science Video Lecture | Science Class 9

Determination of Density of Solid
The density of a material is defined as its
mass per unit volume. If ‘D’ is the density
of a body of mass ‘M’ and volume ‘V’,
then D= M/V.
Here our aim is to determine the density of a solid which is denser than water
by using a spring balance and a measuring cylinder.
Materials Required:
Iron stand, spring balance, lock, cuboid,
wooden block, stone, measuring cylinder, a beaker containing water, thread and scissors
Procedure:
To determine the density of an object, the mass of the object has to be measured.
Hang a spring balance using an iron stand as shown.
Suspend a lock on the hook of the spring balance.
Observe the mass of the lock carefully and
note it down.
To measure the volume of the lock, a graduated
cylinder of proper size and capacity is used.
Fill it with water up to a particular level.
Note the reading.
Cut a piece of thread, tie the lock and then
immerse the lock slowly in the graduated cylinder
containing water by holding the free end of
the twine. The lock displaces water and the
water level rises. Note the current position
of the water level. Find the difference between
the final and initial levels of water which
will give the volume of the lock immersed.
Now we can determine the density of the lock
by using the formula:
Density= ( M/V which is equal to (mass in
gram)/(volume in cm3 )
By the same procedure we can also find the
density of a stone and a wooden block.