Volume and Density

 Hello Visitors! In this article I will be explaining about Volume and density along with it I will discuss how to measure volume of solids, liquids and irregular objects.

First of all I will be solving two problems on Scientific Notations.

Problem #01: Convert the mass of sun 2000000000000000000000000000000kg, into scientific Notation.

Solution:

            Since we are given mass of Sun =Msun= 2 000 000 000 000 000 000 000 000 000 000 kg.

Since according to above question, the decimal point will be in the last. So,

It can be written into Scientific Notation as;

Msun=  2x10^30kg.

Since decimal point will move from Right to Left so power will be Positive.

Problem #02: Convert the mass of an electron 9.11x10^-31kg, into standard form.

Solution:

                We are given Me= 9.11x10^-31 kg.

Now as we already read if decimal point move from left to right, then power will be negativity.

So, shift the decimal point 31 places to the left.

So, Me=0.000 000 000 000 000 000 000 000 000 000911kg

What is Matter?

Anything, which occupies space and has mass is known as Matter.

There are three states of Matter:

• Solid
• Liquid
• Gas

Solid possess following properties:

• Solid has definite size.
• Solid has fixed shape.
  
• Solid has fixed Volume.

Liquid possesses following properties:

Liquid does not has fixed shape.

It takes the shape of the container it is placed in.

Gases possess following properties:

• Gas has no definite shape.
• Gas has no definite Volume.
• Gas Don't has definite size.

Beside these states there is another state of matter available.

4 States of Matter

Measurement of Volume of Liquid

In order to find density, we need to calculate volume.

Most of the solid geometrical shapes has formulas to calculate volume, which are obtained by certain parameters such as, radius,

height, width, base and length.

But the volume of irregular shapes can not be measured this way.

Volume of liquids can be measured using Cylinders and Beakers.

The volume of the liquids is measured by glass or a plastic cylinder.

It has a scale which is graduated in cubic centimeters or millimeters. as shown in figure.

When liquid is poured, it rises to cetain heights in the cylinder.

The level of the liquid in the cylinder is noted and volume of the liquid is obtained.

Measuring the Volume of Regular shape

If the solid has a regular shape its volume can be calculated as;

Volume of rectangular block= Length x Height x Width

Volume of a cylinder= pi^2 x Height.

Measurement of Volume of Irregular shapes

The volume of irregular object can be calculated by Subtracting the original Volume from the raised volume.

The total volume is found.

Density

The term Density can be defined as:

Mass of subtance (m), per unit volume (V).

It is denoted by Greek letter p (rho).

Its Formula can be written as;

p=mass/volume

Its unit is kg/m^3 or g/cm^3

Density is the characteristic property of any substance.

Using above formula mass of any substance can also be calculated as,

                                    m= pV      

There are two ways to calculate density.

Either mathematically or experimentally, by taking density of water at 4C as reference (Specific Gravity) or relative density.

Relative density= Density of Substance/Density of Water

Problem #01: What is the mass of solid iron wrecking ball of 18cm. If the density of iron is 7.8g/cm^3.

Solution:

                We are given;

Density of iron ball = 7.8gm/cm^3= 7.8 x1000 m/m^3

Radius of iron ball r = 18cm =18x10^-2m

Volume= (4/3)xpixr^3

V= 1.33 x 3.142 x  (0.18)^3

V= 0.024m^3

m= pV = (7.8x10^3)(0.024)

m= 187.2kg

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