# Chapter 1 – Physical Quantities and Measurement

The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:

Introduction

You must have experienced visiting a supermarket to buy your groceries. You must have asked the shopkeeper to give you either 2 kg of dal or 5 kg of sugar or so on. In either of the cases, you are quantifying the object that you wish to buy. It is a simple example to understand how physical quantities are measured.

A physical quantity is any object or its property that can be expressed using a numerical value. Few examples, temperature, volume, time, electric current, and so on. Measurement is the standard processing of defining the quantity of any substance.

#### S.I. units for Measurement

Scientists across the globe adopted an international unit of measurements(S.I.) to improve communication.

 Physical quantity S.I. unit for Measurement Symbol Mass Kilogram Kg Length Meter m Time Second s Temperature Kelvin K

Here in this section, we will discuss Measurement of Volume and Density, calculation of speed, and Measurement of area of any given object.

#### Measurement of Volume

Volume is defined as the quantity of space occupied by an enclosed object. In this section, we will see how the volume of different things is measured.

Few of the real-life applications are,

• We measure the volume of liquids while cooking.
• We measure the volume of fuel to be filled in vehicles, and so on.

Volume of a solid object

Consider you have a tangible object whose volume needs to be determined. It can be found by multiplying its length, width, and height.

So, the volume of any solid object= length X breadth X height

Now, consider finding the volume of a cube.

In this case of cube, length=breadth=height=l

So, Measurement of Volume for cube = l3

Thus the standard unit of volume of any solid object is a cubic meter or m3.

Volume of any liquid

Liquids are physical quantities that do not have a definite shape. Thus, a measuring cylinder is used to measure the volume of any liquid. A measuring cylinder is a glass cylinder with markings on the sidewall. You need to pour the liquid and take the reading once it comes to rest.

Measuring cylinder

#### Calculation of Speed

Suppose Arjun and Seema have participated in a 200m race competition in school. Arjun takes 200 seconds, while Seema takes 400 seconds to finish the race. Can you tell me who runs faster?

Here, in this section, you will get an answer to this question.

What is speed?

Speed finds out how fast or how slow an object is moving. It is defined as the distance covered by any object in unit time. Suppose a bike covers a distance of 100 km in 1 hour, then we can say its speed is 100km per hour.

Speed  = Total distance covered(d)/Total time taken(t)

he SI unit of speed is meters/second or m/s. It is measured using a speedometer.

Now let us consider our previous example and calculate the speed for them.

Speed of Arjun=200/200= 1 m/s

Speed of Seema=200/400= 0.5 m/s

Thus, we can say that Arjun runs faster than Seema.

An object covers the maximum distance in a given time when it is travelling at the highest speed. Also, the same thing will cover the minimum distance when it is travelling at the lowest speed.

#### Measurement Of Area

The area is the space occupied by a closed two-dimensional object. In other words, it is the number of squares occupied by a closed flat figure.

In a real-life scenario, we measure the area of the wall to find out the expenses that we might have to bear to paint that wall.

S.I. unit of area is a square meter or m2.

Measurement Of Area Of A Regular Shaped Body

A regularly shaped body or a regular solid is a type of object with a fixed geometrical shape like a plate, compass box, book, etc.

Measurement Of Area Of A Regular Shaped Body using formula gives,

Area of a square = l2, where l is the length

Area of a rectangle=l X b, where l=length and b=breadth

Area of a circle = πr2, where r=radius of circle

Area of a triangle=1/2 x b x h , where b=breadth and h=height

#### Measurement Of Density Of Regular Solid

Consider a wooden ball and a brass ball of equal sizes, i.e., same volumes. Now can you tell which is heavier? Yes, the brass ball is heavier than the wooden ball as it has more mass. Thus, Density is defined as mass per unit volume.

Density= Mass(m)/Volume(v)

A simple example, where a rock sinks in a glass of water, indicates it is denser than water.

S.I. unit of Density is kg/m3.

For Measurement of Density of Regular solid, we would need,

•   Mass of the regular solid that is measured using a weighing scale or any physical balance.
•   The volume of the regular solid that can be measured using the below formulas

Volume of a cube = (length)3

Volume of a cuboid = length X breadth X height

Volume of a cylinder = π r2h , where r= radius and h=height of the cylinder

Volume of a sphere= 4/3 π r3, where r is radius of the sphere

#### Conclusion

Physical quantities and Measurement are expressed using standardized units. Volume is the space occupied by a three-dimensional object, whereas area is the space occupied by two-dimensional objects. An item with a higher density is densely packed as compared to the other things. We increase the vehicle’s speed when there is less traffic and decrease its speed during high traffic.

#### FAQs

1.  Name two instruments that are used for the Measurement of the Volume of a liquid?
A measuring cylinder and measuring beaker are used to measure the volume of the liquid.
2. State the C.G.S unit used for Physical quantities and Measurement?
 Physical quantity C.G.S unit for Measurement Symbol Mass Gram gm Length Centimeter cm Time Second s Temperature Kelvin K

3. Find the measurement of the area of the triangle with a breadth of 4m and a height of 12m.
Area of a triangle= 1/2 x b x h using formula
=
1/2 x 4 x 12
=
212
Area of triangle = 24 m2
4. What care needs to be taken while measuring the volume of a liquid?
The measuring cylinder needs to be kept on a horizontal surface, and the liquid measured should be at rest.
5. If you have steel and glass balls of the same size, which has a higher density?
The steel ball will have a higher density as it is heavier than the glass ball.
6. The speed of the train is 200km/hr while that of an aeroplane is 500km/hr. Which travels faster?
Aeroplanes travel faster than trains.

Students often get confused between when to find the volume of an object and when to find it’s area. With MSVgo, you can understand the concept by watching from a collection of more than 1000 videos and participating in interactive quizzes, games while enjoying the process.

### High School Physics

• Alternating Current
• Atoms
• Communication Systems
• Current Electricity
• Dual nature of Radiation and Matter
• Electric Charges and Fields
• Electricity
• Electromagnetic Induction
• Electromagnetic Waves
• Electron Beams and Radioactivity
• Electrons and Photons
• Electrostatic Potential and Capacitance
• Fluid Pressure
• Force and Acceleration
• Force And Laws Of Motion
• Gravitation
• Internal Energy
• Kinetic Theory
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• Light – Reflection And Refraction
• Magnetic Effects Of Electric Current
• Magnetism and Matter
• Management Of Natural Resources
• Mechanical properties of Fluids
• Mechanical properties of Solids
• Motion
• Motion in a plane
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• Moving Charges and Magnetism
• Nuclear Energy
• Nuclei
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• Our Environment
• Paths of Heat
• Physical world
• Ray optics and optical instruments
• Semiconductor Devices
• Semiconductor Electronics: Materials, Devices and Simple Circuits
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• Spherical Mirrors
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• Systems of Particles and Rotational motion
• Thermal properties of matter
• Thermodynamics
• Units and Measurement
• Vectors, Scalar Quantities and Elementary Calculus
• Wave Optics
• Waves
• Work, Power and Energy

### High School Chemistry

• Acids, Bases and Salts
• Alcohols, Phenols and Ethers
• Aldehydes, Ketones and Carboxylic Acids
• Aliphatic and Aromatic Hydrocarbons
• Alkyl and Aryl Halides
• Amines
• Analytical Chemistry
• Atomic Structure
• Atoms And Molecules
• Basic concepts of Chemistry
• Biomolecules
• Carbon And Its Compounds
• Carboxylic acids and Acid Derivatives
• Chemical Bonding and Molecular Structures
• Chemical Energetics
• Chemical Equilibria
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• Chemical Reactions And Equations
• Chemical Reactions and Their Mechanisms
• Chemistry in Everyday Life
• Chemistry of p-Block elements
• Chemistry of Transition and Inner Transition
• Classification of Elements
• Coordination Compounds
• Cyanide, Isocyanide, Nitro compounds and Amines
• Electrochemistry
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• Elements, Compounds and Mixtures
• Environmental Chemistry
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• Periodic Classification of Elements
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• Principles and Processes of Isolation of Elements
• Redox Reactions
• Relative Molecular Mass and Mole
• States of Matter
• Structure Of The Atom
• Study of Compounds
• Study of Gas Laws
• Study of Representative Elements
• Surface Chemistry
• The d-block and f-block elements
• The Gaseous State
• The p-Block Elements
• The Periodic Table
• The s-Block Elements
• The Solid State
• Thermodynamics

### High School Biology

• Absorption and Movement of Water in Plants
• Adolescent Issues
• Anatomy of Flowering Plants
• Animal Kingdom
• Bacteria and Fungi-Friends and Foe
• Biodiversity and Conservation
• Biofertilizers
• Biological Classification
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• Biomolecules
• Biotechnology and its Applications
• Biotic Community
• Body Fluids and Circulation
• Breathing and Exchange of Gases
• Cell – Unit of Life
• Cell Cycle and Cell Division
• Cell Division and Structure of Chromosomes
• Cell Reproduction
• Cellular Respiration
• Chemical Coordination and Integration
• Circulation
• Control And Coordination
• Crop Improvement
• Digestion and Absorption
• Diversity In Living Organisms
• Ecosystem
• Environmental Issues
• Excretory Products and their Elimination
• Flowering Plants
• Genes and Chromosomes
• Health and Diseases
• Health and Its Significance
• Heredity And Evolution
• Heredity and Variation
• How Do Organisms Reproduce?
• Human Diseases
• Human Eye And Colourful World
• Human Health and Disease
• Human Population
• Human Reproduction
• Hygiene
• Improvement In Food Resources
• Integumentary System- Skin
• Kingdom Fungi
• Kingdom Monera
• Kingdom Protista
• Life Processes
• Locomotion and Movement
• Microbes in Human Welfare
• Mineral Nutrition
• Molecular Basis of Inheritance
• Morphology of Flowering Plants
• Neural Control And Coordination
• Nutrition in Human Beings
• Organism and Population
• Photosynthesis
• Photosynthesis in Higher Plants
• Plant Growth and Development
• Plant Kingdom
• Pollination and Fertilization
• Pollution; Sources and its effects
• Principles of Inheritance and Variation
• Reproduction and Development in Angiosperms
• Reproduction in Organisms
• Reproductive Health
• Respiration in Human Beings
• Respiration in Plants
• Respiratory System
• Sexual Reproduction in Flowering Plants
• Strategies for Enhancement in Food Production
• Structural Organisation in Animals
• Structural Organisation of the Cell
• The Endocrine System
• The Fundamental Unit Of Life
• The Living World
• The Nervous System and Sense Organs
• Tissues
• Transpiration
• Transport in Plants

### High School Math

• Algebra – Arithmatic Progressions
• Algebra – Complex Numbers and Quadratic Equations
• Algebra – Linear Inequalities
• Algebra – Pair of Linear Equations in Two Variables
• Algebra – Polynomials
• Algebra – Principle of Mathematical Induction
• Algebra – Quadratic Equations
• Binomial Theorem
• Calculus – Applications of Derivatives
• Calculus – Applications of the Integrals
• Calculus – Continuity and Differentiability
• Calculus – Differential Equations
• Calculus – Integrals
• Geometry – Area
• Geometry – Circles
• Geometry – Conic Sections
• Geometry – Constructions
• Geometry – Introduction to Euclid’s Geometry
• Geometry – Three-dimensional Geometry
• Geometry – Lines and Angles
• Geometry – Quadrilaterals
• Geometry – Straight Lines
• Geometry – Triangles
• Linear Programming
• Matrices and Determinants
• Mensuration – Areas
• Mensuration – Surface Areas and Volumes
• Number Systems
• Number Systems – Real Numbers
• Permutations and Combinations
• Probability
• Sequence and Series
• Sets and Functions
• Statistics
• Trignometry – Height and Distance
• Trignometry – Identities
• Trignometry – Introduction

### Middle School Science

• Acids, Bases And Salts
• Air and Its Constituents
• Basic Biology
• Body Movements
• Carbon and Its Compounds
• Cell – Structure And Functions
• Changes Around Us
• Chemical Effects Of Electric Current
• Chemistry in Your Life
• Coal And Petroleum
• Combustion And Flame
• Components Of Food
• Conservation Of Plants And Animals
• Crop Production And Management
• Electric Current And Its Effects
• Electricity And Circuits
• Elements and Compounds
• Fibre To Fabric
• Food production and management
• Force And Pressure
• Forests: Our Lifeline
• Friction
• Fun With Magnets
• Garbage In, Garbage Out
• Getting To Know Plants
• Health and Hygiene
• Heat
• Hydrogen
• Life Processes: Nutrition in Animals and Plants
• Light, Shadows And Reflections
• Materials: Metals And Non-Metals
• Matter and Its States
• Metals and Non-metals
• Micro Organisms: Friend And Foe
• Motion And Measurement Of Distances
• Motion And Time
• Nutrition In Animals
• Nutrition In Plants
• Organization in Living Things
• Our Environment
• Physical And Chemical Changes
• Pollution and conservation
• Pollution Of Air And Water
• Reaching The Age Of Adolescence
• Reproduction In Animals
• Reproduction In Plants
• Respiration In Organisms
• Rocks and Minerals
• Separation Of Substances
• Simple Machines
• Soil
• Some Natural Phenomena
• Sorting Materials Into Groups
• Sound
• Stars And The Solar System
• Structure of Atom
• Synthetic Fibers And Plastics
• The Living Organisms And Their Surroundings
• Transfer of Heat
• Transformation of Substances
• Transportation In Animals And Plants
• Universe
• Waste-water Story
• Water: A Precious Resource
• Weather, Climate And Adaptations Of Animals To Climate
• Winds, Storms And Cyclones

### Middle School Math

• Addition
• Area and Its Boundary
• Boxes and Sketches
• Data Handling
• Fun With Numbers
• Heavy and Light
• How Many
• Long And Short
• Mapping
• Measurement
• Money
• Multiplication and Factors
• Multiply and Divide
• Numbers
• Parts and Wholes
• Pattern Recognition
• Patterns
• Play With Patterns
• Rupees And Paise
• Shapes And Angles
• Shapes And Designs
• Shapes and Space
• Similarity
• Smart Charts
• Squares
• Subtraction
• Tables And Shares
• Tenths and Hundredths
• Time
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