Materials Around Us Class 6 Question Answer

 Materials Around Us Class 6 Question Answer

Every day we use many things in our life – a chair to sit on, clothes to wear, utensils for cooking, books to study, toys to play with, and vehicles to travel. All these things are made of different materials such as wood, plastic, cotton, glass, iron, and paper. Some materials are natural, while others are man-made. Each material has special properties that make it useful for a particular purpose. For example, glass is used for making windows because it is transparent, while wood is used for furniture because it is strong and durable.

In this chapter, we will learn about the different kinds of materials around us, their properties, and their uses. We will also try to understand how scientists and engineers choose the right material to make useful things in our daily life.

Materials Around Us Class 6 Question Answer

1:-What are natural objects?

Ans:- Object that are made by nature is Called natural is called natural object.

      Ex:- Sky, Sun, Moon, Air, Water etc.

2:-What are man made object?

Ans:- Objects that are made by man are called man made object.

     Ex:- Fan, Table, Pen etc.

3:- What is material?

Ans:- The substance which is used to make an object is called substances.

        Ex:- Wood, Soil, Ghee etc.

4:- What is matter?

Ans:- Anything which has volume and mass is called matter.

       Ex:- Book, Bed etc.

5:- What is volume?

Ans:- The space occupied by an object is called its volume.

6:-How many type of matter on the basis of appearance

Ans:- There are two types of matter on the basis of appearance.

   1-lustrous substance

   2-Non-lustrous substance

7:-What is lustrous substance?

Ans:- The substance that has special sine that is luster is called lustrous substance. Metals have such luster. 

   Ex:- iron, copper, aluminium, gold etc.

8:-What is Non-lustrous substance?

Ans:- The substance that has no special sine is called Non-lustrous substance. It is also called dull substance Ex:- paper, wood, cotton, chalk etc.

9:-How many types of material on the basis of roughness and smoothness?

Ans:- There are two types of material on the basis of roughness and smoothness

   1- Rough material

   2- Smooth material

10:-What is rough material?

Ans:- The material which has bumps or ridges on its surface is called rough material.

   Ex:- rocks, barks of tree etc

11:-What is smooth material?

Ans:- The material which has no bumps or ridges on its surface is called smooth material.

   Ex:- glass sheet, flower petals etc

12:-How many types of material on the basis of hardness?

Ans:- There are two types of material on the basis of hardness

   1- soft material

   2- hard material

13:-What is soft material?

Ans:- The material that can be pressed easily by our hands is called soft material.

   Ex:- rubber, wax etc

14:-What is hard material?

Ans:- The material that can not be pressed easily by our hands is called hard material.

   Ex:- stone, iron etc

15:- How many types of matter on the basis of state?

Ans:- There are three types of matter on the basis of state.

  1- Solid

  2- Liquid

  3- Gas

16:- What is solid? Write its properties.

Ans:- Matter which have fixed shape and volume is called solid.

         Ex:- Ice, Bricks, Wood etc.

Properties of solid

   1- The molecules in solid state are tightly packed, therefor solids are hard, strong and rigid materials.

   2-  The distance between molecules in solids is very small, therefor they can not be easily compressed.

   3- The molecules in solid do not have a free movement. Molecules can only vibrate about their fixed positions. they can not flow.

   4- Solids have definite shape , size and volume because they have strong intermolecular space.

   5- In solid diffusion is very slow compared to liquids and gases.

17:- What is liquid? Write its properties.

Ans:- Matter which have fixed volume but does not fixed shape is called liquid.

         Ex:- Water, Milk, Oil etc.

Properties of liquid

   1- The distance between molecules in liquids is larger than the solid, hence liquids can compressed a little but not easily.

   2- The molecules of liquids have an easy movement, so they can floe easily.

   3-liquids have no definite shape because they have weak intermolecular force. Therefor liquids take the shape of container in which they are kept in.

   4- liquids have definite volume.

   5- Liquids can diffuse into other liquids or gases, but slower than gases.

18:- What is gas? Write its properties.

Ans:- Matter which does not have fixed shape and volume is called gas.

          Ex:- Air, Water vapour etc.

Properties of gases

   1- The distance between molecules in gases is very large. Therefor gases can be compressed easily.

   2- The molecules of gases have free random movement so gases can flow easily in all direction.

   3- Gases can diffuse easily to each other.

   4- Gases have neither definite shape nor a definite volume because of weak intermolecular force.

   5- Moving gas particles collide with the walls of the container, creating pressure.

   6- Gases expand to completely fill any container, no matter the size

   7- Gas volume and pressure change significantly with changes in temperature or external pressure 

19:- What is evaporation?

Ans:- Evaporation is the process by which a substance changes from liquid phase to the gasious phase.

  Ex:- Water boils to become water vapour.            

6:- What is condensation?

Ans:- Condensation is the process by which a substance changes from gasious phase to the liquid phase.

      Ex:- Water vapour cools to become water.

20:-What is Diffusion?

Diffusion is the process by which particles move from an area of high concentration to an area of low concentration, until they are evenly spread out. It happens naturally without requiring extra energy.

Ex:- Smell of perfume spreading across a room.

        Sugar dissolving and spreading in water without stirring.

        Oxygen moving from the lungs into the blood. 

21:- What is inter molercular force?

Ans:- The force of attraction that is found between two molecules of same matter is called inter molecular force.

* The inter molecular force is greatest in solid. The inter molecular force of liquid is less than solid but greater than gas.The inter molecular force of gas is very less than both solid and liquid.

22:- What is inter molecular space?

Ans:- The space that is found between two molecules of the same matter is called inter molecular space.

* The molecular space is greatest in gas . The molecular space in liquid is less than gas greater than solid. The molecular space in solid is very less than both liquid and gas.

23:- Why does a solid retain their fixed shape and fixed volume?

Ans:- Solid retains fixed shape and fixed volume because it has very strong molecular force. Molecular force keeps the molecules of solid tightly packed to each other.

24:-Why does a gas riten their unfixed shape and volume?

Ans:- Gas retains unfixed shape and volume because it has very negligible molecular force. 

25:- What is metal? 

Ans:- Those opaque lustrous elements that are good conductor of heat and electricity is called metal.

       Ex:- Iron, Copper etc.

26:- Write six properties of metal.

Ans:- The six propertied of metal are.

 1- Metals have a special sign called lustrous.

2- Metals are flexible. It can be easily bent.

3- Metals are good conductor of heat.

4- Metals are good conductor of electricity.

5- Metals are mallable. They can be beaten into thin sheets.

6- Metals are ductile. They can be drawn into wire.

27:- Write five uses of metals.

Ans:- The five uses of metals are.

1- Metals are used to make kitchen utensils.

2- Metals are used to make electrical cables.

3- Metals are used to make machines.

4- Metals are used to make scientific instrument.

5- Metals are used in make jwellry.

28:-  Write eight properties of glass.

Ans:- The eight properties of glass.

1- Glass is shiny

2- Glass is smooth

3- Glass is hard

4- Glass is non- flexible

5- Glass is brittle

6- Glass is non- conductor of heat and electricity

7- Glass is transpatent

8- Heated glass can be moulded to any shape.

29:- Write five uses of glass.

Ans:- The five uses of glass are.

1- Glass is used  to make science upparatus.

2- Glass is used to make strong bottles.

3- Glass is used to make elerctric bulbs.

4- Glass is used to make doors and windows.

5- Glass is used to make mirrors.

30:- Write six properties of plastic.

Ans:- The six properties of plastic are.

1- Plastic is flexible.

2- Plastic floats on water.

3- Plastic melts on heating easily.

4- Plastic can be moulded to any shape.

5- Plastic catches fire on flame easily.

6- Plastic may be transparent or translucent.

31:- Write four uses of plastic.

Ans:- The four uses of plastic are.

1- It is used for making items of kitchen.

2- It is used for making electric switches.

3- It is used for making house hold items like table, chair etc.

4- It is used for making car bodies.

32:- Write four properties of water.

Ans:- The four properties of water are.

1- Water has no shape of its own.

2- Water is colourless.

3- Water is odourless.

4- Water aquires the shape of the vessels in which it is poured.

33:- Write two materials that are rough in natute.

Ans:- Bark of tree, sand paper.

34:- Write two materials that are smooth in nature.

Ans:- Sheets of glass, Floor tiles.

35:- Write two metals that are more lustrous.

Ans:- Gold, Silver.

36:-What is transparency?

Ans:- Transparency is the property of a material or object that allows light to pass through it so that objects behind can be clearly seen.

37:-How many types of material on the basis of transparency?

Ans:- There are three types of material on the basis of transparency.

   1-Transparent

   2-Translucent

   3-opaque

38:- What is transparent materials?

Ans:- Those materials by which light can pass easily and completely are called transparent maerials.

      Ex:- Glass, Acrylic, Air etc.

39:- What are translucent materials?

Ans:- Those materials by which light can pass partially and we can not see clearly through them are called translucent materials.

     Ex:- Frosted glass, Milky water.

40:- What are opaque materials? Write example.

Ans:- Those materials that do not allow the light to pass through them are called opaque materials.

        Ex:- Wood, Metal sheet, Rock etc.

41:-How many types of matter on the basis of conduction of heat?

Ans:- There are two types of matter on the basis of conduction of heat.

   1- conductor

   2- insulator

42:- What is conductor? Write example.

Ans:- The material that allows heat and electricity to flow through them from one end to another very quickly is called conductor.

     Ex:- Iron, Copper, Silver, etc.

43:- What is insulator? Write example.

Ans:- The material that does not allows heat and electricity to pass through them is called insulator.

       Ex:- Rubber, Wood, Cardboard etc.

44:-How many types of material on the basis of magnetism?

Ans:- There are two types of material on the basis of magnetism

   1- magnetic material

   2-Non-magnetic material

45:-What is magnetic material?

Ans:- The material which is attracted towards a magnet is called magnetic material.

Ex:- iron, steel, cobalt etc

46:-What is non-magnetic material?

Ans:- The material which is not attracted towards a magnet is called non-magnetic material.

Ex:- wood, plastic, cotton etc

47:- How many types of material on the basis of solubility?

Ans:- There are two types of material on the basis of solubility.

   1- soluble substance

   2-insoluble substance

48:-What is soluble substance?

Ans:- A material that can dissolve in a solvent to form a solution is called soluble substance.

Ex:- Salt (NaCl) dissolves in water to give salty water.

       Sugar (C₁₂H₂₂O₁₁) dissolves in water to give sweet water.

49:-What is insoluble substance?

Ans:- A material that can not dissolve in a solvent to form a solution is called insoluble substance.

Ex:- wax can not dissolves in water .

       Sugar (C₁₂H₂₂O₁₁) can not dissolves in petrol.

Solute = the substance that dissolves is called solute.

Ex:- salt, sugar etc

Solvent = the liquid in which the solute dissolves is called solvent.

Ex:- water, milk etc

Solution = the uniform mixture formed by the help of solute and solvent is called solution.

50:- Write two materials that are soluble in water.

Ans:- Sugar and Salt.

51:- Write two materials that are insoluble in water.

Ans:- Sand and Wax.

52:- Write a material that is soluble in kerosene.

Ans:- Wax

53:-What are miscible liquids?

Ans:- Miscible liquids are liquids that can mix together in any proportion to form a single uniform solution without separating into layers.

Ex:- Water and alcohol, Water and vinegar

54:-What are immiscible liquids?

Ans:- liquids that do not mix and instead this  form separate layers are called immiscible liquids.

Ex:- oil and water

55:- Write four liquids that are miscible in water.

Ans:- Glycerine, Vinegar, Alcohol and honey.

56:- Write two liquids that are immiscible in water.

Ans:- Mustard oil, Kerosene.

57:- Write two liquids that are miscible in mustard oil.

Ans:- Groundnut oil, Coconut oil.

58:- Write a liquids that is miscible in kerosene.

Ans:- Petrol

59:- Write two gases that is not soluble in water.

Ans:- Nitrogen , methane

60:- Write two gases that is partly miscible in water.

Ans:- Carbon- dioxide, oxygen.

 

61:-What is Density?

Ans:- The mass of substance per unit volume is called its Density. A substance which is denser than water will sink while substance which is less dense than water will float.

62:- Why does wood float in water?

Ans:- Wood floats in water because the density of wood is less than the density of water.

63:- Why does an iron nail sink in water?

Ans:- Iron nail sinks in water because the density of iron nails is greater than the water.

Introduction to the human body - Our Body class 1

Introduction to the human body - Our Body class 1

Our body is amazing! It helps us do everything—like running, jumping, eating, and playing. We have many body parts, and each one has a special job. Some parts help us see and hear, while others help us move or think.

In this chapter, we will learn about the different parts of our body and what they do. Let’s explore how our body works and why it is important to take care of it!

 

Introduction to the human body - Our Body class 1

Our body is like a machine. It has many parts like legs, hands, face, and five sense organs etc. Each parts performs a specific function. There are two types of parts of human body

1- internal parts of human body

2- external parts of human body

All parts of our body are very important because they help us.

Different External body parts

Legs

legs help us to walk, run, jump, kick, skip and dance. They carry our body weight.

Hands

Hands help us to hold, throw, catch things, carry things, write, push and pull. We eat with hands. We play with the help of hands.

Our Face

our eyes, nose, ears and mouth are parts of our face. We are identified by our face.

Sense organs

The organs of our body that help us to enjoy the things around us are called sense organs. 

The five sense organs are eyes, nose, ears, tongue and skin.

eyes

Eyes help us to see.

Nose

Nose helps us to smell.

Ears

Ears help us to hear.

Tongue

Tongue helps us to taste and speak.

Skin

Skin helps us to feel and touch.

Fingers

I have five fingers in each hand. They are Thumb, Index finger, middle finger, ring finger and baby finger.

Some important question

1:- How many ears do you have?

Ans:- I have two ears.

2:- How many nose do you have?

Ans:- I have one nose.

3:- How many eyes do you have?

Ans:- I have two eyes.

4:- How many fingers do you have in each hand?

Ans:- I have five fingers in each hand. 

5:- Write the name of five fingers of our hand?

Ans:-Thumb, Index finger, middle finger, ring finger and baby finger

6:- How many times do we breathe in a day?

Ans:-We breathe 23000 times in a day.

7:- How many times do we blink in a day?

Ans:-We blink 25000 times in a day.

Read More

• Science class 1
• Science class 2
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Daily use items that make life easier- Home & Office Edition

 Daily use items that make life easier- Home & Office Edition - In our fast-paced lives, having the right daily use items can significantly improve efficiency, comfort, and overall well-being. From morning routines to bedtime rituals, these essentials make everyday tasks easier and more convenient. Whether you're a busy professional, a student, or managing a household, incorporating smart and functional items into your daily routine can save time, reduce stress, and enhance productivity.

Items like reusable water bottles, meal prep containers, power banks, noise-canceling earphones, and planners help keep you organized and energized throughout the day. In the kitchen, tools such as electric kettles, microwavable lunch boxes, and multipurpose cleaners simplify cooking and cleaning. For personal care, essentials like grooming kits, skincare products, and compact mirrors ensure you're always ready, even on the go.

Technology also plays a key role—smart home devices, USB chargers, and portable fans are now common daily needs that make living more comfortable. These practical tools aren’t just about luxury; they’re about making life smoother and more manageable. Investing in the right daily use items isn't just smart—it’s necessary in today’s world. Explore this list of life-enhancing essentials and discover how small changes can make a big difference in your everyday routine.

आज की तेज़ रफ्तार ज़िंदगी में कुछ रोज़मर्रा की उपयोगी चीज़ें हमारे जीवन को न केवल आसान बनाती हैं, बल्कि समय और मेहनत भी बचाती हैं। चाहे आप एक छात्र हों, ऑफिस में काम करने वाले हों या घर संभालने वाले व्यक्ति, सही दैनिक उपयोग की चीज़ें आपके दिनभर के काम को व्यवस्थित और सुविधाजनक बना सकती हैं।

पानी की बोतल, टिफिन बॉक्स, पावर बैंक, प्लानर, और इयरफोन्स जैसी चीज़ें रोज़ की जरूरत बन चुकी हैं। ये न केवल आपके काम को आसान बनाती हैं बल्कि आपको दिनभर सक्रिय भी रखती हैं। रसोई के लिए इलेक्ट्रिक केतली, मल्टीपरपज़ क्लीनर, और माइक्रोवेव सेफ कंटेनर जैसे सामान खाना पकाने और सफाई को तेज़ और आसान बनाते हैं।

व्यक्तिगत देखभाल के लिए ग्रूमिंग किट, स्किन केयर प्रोडक्ट्स और छोटे मिरर आपके साथ रहकर आत्मविश्वास बढ़ाते हैं। इसके साथ ही, स्मार्ट डिवाइस, चार्जर, और पोर्टेबल फैन जैसी तकनीकी चीज़ें जीवन को और आरामदायक बना देती हैं।

Daily use items that make life easier- Home & Office Edition 

यह ब्लॉग उन जरूरी चीज़ों की सूची है जो आपके रोज़मर्रा के जीवन को बेहतर बना सकती हैं। छोटे बदलावों से बड़ा फर्क संभव है—बस सही चीज़ें चुननी होंगी।

Collection:- 2

A cooking oil dispenser is a convenient kitchen tool designed for mess-free, precise pouring of oil. It helps control oil usage, promotes healthier cooking, and keeps your kitchen clean. With a sleek design and easy-to-use spout, it's perfect for everyday cooking, baking, and dressing salads efficiently.

कुकिंग ऑयल डिस्पेंसर एक उपयोगी रसोई उपकरण है जो तेल को साफ-सुथरे और नियंत्रित तरीके से डालने में मदद करता है। यह तेल की मात्रा पर नियंत्रण रखता है, हेल्दी कुकिंग को बढ़ावा देता है और रसोई को गंदा होने से बचाता है। रोज़ाना उपयोग के लिए यह बेहद सुविधाजनक है।

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Collection:- 1

A cooking oil dispenser is a convenient kitchen tool designed for mess-free, precise pouring of oil. It helps control oil usage, promotes healthier cooking, and keeps your kitchen clean. With a sleek design and easy-to-use spout, it's perfect for everyday cooking, baking, and dressing salads efficiently.

कुकिंग ऑयल डिस्पेंसर एक उपयोगी रसोई उपकरण है जो तेल को साफ-सुथरे और नियंत्रित तरीके से डालने में मदद करता है। यह तेल की मात्रा पर नियंत्रण रखता है, हेल्दी कुकिंग को बढ़ावा देता है और रसोई को गंदा होने से बचाता है। रोज़ाना उपयोग के लिए यह बेहद सुविधाजनक है।

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The Toppers' Shelf | competitive exam book | competitive exam important book

 The Toppers' Shelf | competitive exam book - competitive exam important book- Competitive exam books play a vital role in the preparation journey of aspirants aiming to secure government jobs, admission to prestigious institutes, or other career opportunities. These books are specially designed to cater to the syllabus and pattern of various competitive exams such as UPSC, SSC, Banking, Railway, NEET, JEE, and more.

One of the key advantages of competitive exam books is that they provide structured content, which helps students understand complex topics in a simplified manner. They include detailed explanations, solved examples, practice questions, and previous years’ papers that help in better conceptual clarity and time management.

Moreover, these books often include tips, shortcuts, and strategies to solve questions efficiently, which is crucial in time-bound exams. High-quality competitive books are curated by subject experts and often updated as per the latest exam patterns, making them reliable resources.

In today’s digital age, while online resources are available, well-organized books remain a trusted tool for focused and distraction-free learning. They build a strong foundation and enhance self-study habits. Hence, choosing the right competitive exam books is essential for effective preparation, confidence-building, and ultimately, success in the chosen exam.

प्रतियोगी परीक्षा की तैयारी करने वाले छात्रों के लिए पुस्तकों का बहुत अधिक महत्व होता है। ये पुस्तकें विशेष रूप से UPSC, SSC, बैंकिंग, रेलवे, NEET, JEE जैसी परीक्षाओं के पाठ्यक्रम और परीक्षा पैटर्न को ध्यान में रखकर तैयार की जाती हैं।

प्रतियोगी परीक्षा की पुस्तकें विषयों को सरल और क्रमबद्ध तरीके से समझाने में मदद करती हैं। इनमें विस्तृत व्याख्याएं, हल किए गए उदाहरण, अभ्यास प्रश्न और पिछले वर्षों के प्रश्नपत्र शामिल होते हैं, जिससे छात्रों को बेहतर समझ और समय प्रबंधन में सहायता मिलती है।

इन पुस्तकों में अक्सर शॉर्टकट्स, टिप्स और रणनीतियाँ भी दी जाती हैं जो सीमित समय में प्रश्नों को हल करने में मददगार होती हैं। अच्छे लेखक या विशेषज्ञों द्वारा तैयार की गई ये पुस्तकें विश्वसनीय और नवीनतम परीक्षा पैटर्न पर आधारित होती हैं।

हालांकि आजकल ऑनलाइन संसाधन भी उपलब्ध हैं, लेकिन पुस्तकों के माध्यम से अध्ययन एकाग्रता और आत्म-अध्ययन की आदत को बढ़ाता है। इसलिए, सही प्रतियोगी परीक्षा पुस्तकों का चयन करना सफलता की दिशा में एक महत्वपूर्ण कदम होता है।

The Toppers' Shelf | competitive exam book 

यहाँ कुछ महत्वपूर्ण प्रतियोगी परीक्षा पुस्तकों की जानकारी दी जा रही है, जिन्हें पढ़कर आपकी तैयारी आसान होगी और सफलता पाने का आत्मविश्वास बढ़ेगा। जरूर पढ़ें!

competitive exam important book- 1

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Latest Women's Fashion Trends: 2025 Ki Top Clothing Picks | ladies new trend | Style Your Way: Affiliate Finds & Wardrobe Hacks

 Latest Women's Fashion Trends: 2025 Ki Top Clothing Picks | Style Your Way: Affiliate Finds & Wardrobe Hacks - Women's fashion trends in 2025 have taken a fresh and stylish turn. This year, comfort meets elegance with a strong focus on sustainable fabrics, soft pastel shades, and relaxed silhouettes. From co-ord sets and flowy maxi dresses to denim-on-denim looks and subtly embroidered ethnic wear, there's something for every woman. High-waisted trousers paired with crop tops, layered kurtis, and outfits with statement sleeves are dominating wardrobes. Fashion influencers and designers alike are embracing bold prints and experimental cuts. Whether you're dressing for a casual day out or a festive occasion, 2025’s top fashion picks offer the perfect blend of tradition and modernity. In this blog, we bring you the most trending outfit ideas and styling tips to upgrade your wardrobe and stay ahead in the fashion game.

2025 की महिलाएं फैशन ट्रेंड्स में नया अंदाज़ और ताज़गी देखने को मिल रही है। इस साल आराम और स्टाइल दोनों को बराबर महत्व दिया गया है। सस्टेनेबल फैब्रिक, हल्के पेस्टल शेड्स और ढीले-ढाले सिल्हूट्स का क्रेज़ ज़ोरों पर है। को-ऑर्ड सेट्स, फ्लोई मैक्सी ड्रेसेज़, डेनिम ऑन डेनिम लुक और हल्के कढ़ाई वाले एथनिक कपड़े महिलाओं के बीच बेहद पॉपुलर हो रहे हैं। क्रॉप टॉप्स के साथ हाई-वेस्ट ट्राउज़र्स, लेयर्ड कुर्तियाँ और स्टेटमेंट स्लीव्स भी फैशन में ट्रेंड कर रहे हैं। डिज़ाइनर्स और फैशन इंफ्लुएंसर्स बोल्ड प्रिंट्स और नए कट्स को खूब पसंद कर रहे हैं। अगर आप भी अपना वॉर्डरोब अपग्रेड करना चाहती हैं |

Latest Women's Fashion Trends: 2025 Ki Top Clothing Picks

2025 के ये टॉप फैशन पिक्स आपके लिए एक परफेक्ट गाइड साबित होंगे। इस ब्लॉग में जानिए लेटेस्ट ट्रेंड्स और स्टाइलिंग टिप्स – ताकि हर मौके पर दिखें स्टाइलिश और आत्मविश्वास से भरपूर। 

Collection:- 4

फ्लोरल प्रिंट वाला यह कुर्ता महिलाओं के लिए आकर्षकता और आराम का सुंदर मेल है। मुलायम और सांस लेने वाले कपड़े से बना, यह ताजगी से भरे फूलों के प्रिंट के साथ खास लुक देता है। रोज़मर्रा या त्योहारों पर पहनने के लिए एकदम उपयुक्त और स्टाइलिश विकल्प है।

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Collection:- 3

बच्चों के लिए साड़ी एक सुंदर, हल्की और पहनने में आसान पारंपरिक पोशाक है, जो त्योहारों, सांस्कृतिक कार्यक्रमों और ड्रेस-अप के लिए बिल्कुल उपयुक्त होती है।

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Collection:- 2

 Ladies pants offer comfort and style for every occasion. From casual wear to formal looks, they come in various fabrics, fits, and colors to suit every woman’s fashion needs.

लेडीज़ पैंट्स एक आरामदायक और स्टाइलिश परिधान है, जो रोज़मर्रा की जिंदगी से लेकर ऑफिस और खास मौकों तक के लिए उपयुक्त होती हैं। ये विभिन्न डिज़ाइनों, रंगों और फैब्रिक में उपलब्ध होती हैं, जिससे हर महिला अपनी पसंद और ज़रूरत के अनुसार इन्हें चुन सकती है।

यह  meesho(मीशो) पर उपलब्ध है|

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Collection:- 1

नई ट्रेंडिंग चंदेरी कुर्तियों की खूबसूरती अब हर महिला की पसंद बन गई है। हल्के वजन और हल्की चमक वाले इस कपड़े की कुर्तियां त्योहारों और रोज़मर्रा के पहनावे के लिए परफेक्ट हैं। खूबसूरत प्रिंट और नाज़ुक कढ़ाई के साथ ये कुर्तियां हर लुक में शान बढ़ाती हैं। यह कुर्ती meesho(मीशो) पर उपलब्ध है|

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Knowledge Hub

Motion class 9 physics NCERT

Motion

Introduction

State (State of a body)

-        Rest

-        Motion

Physical quantities and sytem of a unit

Distance and displacement

Speed, Velocity

Average speed and average velocity

Uniform and non uniform motion

Accleration

Uniform and non uniform acceleration

Equation of motion

Circular motion

Graphical representation of motion

In physics there are two state of an object

1-     Rest/Stationary

2-     Motion

Rest/stationary state of an object

An object is said to be in rest when at does not change its position with the respect of their surrounding.

In rest state an object has fixed position

Ex-  tree , house , electric pole , factory etc.

Motion state of an object

An object is said to be in motion when its position changes continuously with respect to a stationary object taken as reference point.

It the phenomenon in which an object changes its position with respect to tire.

  Ex:-flying birds, rotating planets, swimming fishes

Physical quantities

All  those quantities which can be measured is called physical quantities

  Ex:- length, mass, time, temperature, force, pressure, work

There are two types of physical quantities

1- scalar quantities

2- Vector quantities

Scalar quantities

Those quantities whose magnitude is fixed but direction is not fixed are called scalar quantities. They are are not dependent on direction, they can described only by magnitude.

  Ex:- length, mass, time, temperature, density etc.

the symbol of scalar quantities are represented simply

  ex_ distance - d

          time - t

 

Vector quantities 

Those quantities whose magnitude and direction both are fixed are called vector quantities. They are dependent on both direction as well as magnitude.

Ex:- force 

 the symbol of vector quantities are represented by an arrow.

  ex- force - →

                    F

             System of units

those tools which can be used to measure the physical quantities effectively is called system of unit. They are standardized value so that they are acceptable in every country.

Measurement of physical quantities are expressed in terms of unit which are standardized value.

                                                                                    -SI system-

International system of unit-

The international system of units (SI) is the metric system that is used universally as a standard for measurements.

It is used universally in technical and scientific research to avoid the confusion with the units. It is important because it helps the entire world to understand the measurement in one set of unit systems.

Name of quantity                                      SI. unit                                                     SI. unit symbol

Length                                                       meter                                                            m

Mass                                                          kilogram                                                       kg

Time                                                          second                                                           s

Electric current                                          ampere                                                          A

Thermodynamic temperature                    Kelvin                                                            K

Amount of substance                                 mole                                                              Mol

Luminous intensity                                    candela                                                          cd

The SI system is made of seven base units and these seven base units are used to define twenty two derived units.

The seven base units are:-

1- meter (m)

2- second (s)

3- Ampere (A)

4- Mole (Mol)

5- Kilogram (kg)

6- Kelvin (K)

7- candela (cd)

There are three types of system of units:-

1- MKS

2- CGS

3- FPS

                                                          Distance and displacement

Distance is the actual length of the path by a moving body irrespective of the direction in which the body travels.

                Total distance = 4km + 2km + 8km

          It is a scalar quantity Distance is represented by 'd'

                                             - Displacement-

The shortest distance between the initial position and final position of the body along with direction is known as displacement.

Note :- The symbol by which initial position represents are 'pi'. The symbol by which final are 'pf'.

Displacement is represented by the symbol 's'

:. s = pf - pi

Calculate the Displacement in given figure.

Calculate the distance and displacement in given figure.

Note:- Distance never becomes zero but sometimes displacement becomes sometimes zero.

What is the displacement of a car when it moving around a circular park when final position and initial position are same.

Is displacement becomes zero on straight path.

 

Describe speed?

Ans:- Speed of  the body is the distance traveled by the body in per unit time. It gives an idea of how slow or fast that body is moving. Speed is a scalar quantity as it has only direction and no magnitude.

Speed is measured as the ratio of distance to the time in which the distance was covered.

∴ S = d / t

;.ijlwhere S = speed in m/s 

           d = distance traveled in m

           t = time taken in second

The SI unit of speed is m/s

The unit of speed in CGS system is cm/s

There are four types of speed.

1- Uniform speed-An object is said to be in uniform speed when the object covers equal distance in equal time intervals.

Ex:- rotation of earth, revolution of earth, pendulum etc.

2- Variable speed- An object is said to be in variable speed when the object covers a different distance at equal interval of time.

3- Average speed- Average speed is defined as the uniform speed which is given by the ratio of total disntance travelled by an object to the total time taken by the object.

4- Instantaneous speed- When an object is moving with variable speed, than the speed of that object at any instant of time is known as instantaneous speed.

Explain Velocity

The distance traveled by a body in per unit of time in a given direction is called velocity of the body. Velocity is a vector quantity as it has magnitude as well direction. Velocity gives an idea of direction of motion.

Velocity of a body is the displacement produced per unit of time

∴ velocity = distance traveled in a given time / time taken

  →                                                                                                                                                                 ∴ V = Displacement / time

→                                                                                                                                                                 ∴ V = change in position in a particular direction / time

→                                                                                                                                                                 ∴ V =  P_f – P_i /t

The SI unit of velocity is m/s

Numerical-1

A car travels a distance of 100 km in 2 hr. Calculate speed of the car.

Numerical-2

A car travels a distance of 100 km in east in 2 hr. Calculate speed of the car.

Numerical-3

A boy goes to the soap that is 100m far from his home and return to the home back in 40 second. find its speed. 

Numerical-4

A boy goes to the soap that is 100m far from his home and return to the home back in 40 second. find its velocity.

Uniform / Non-uniform motion

Uniform motion:- When a body travels equal distances in equal intervals of time. than the motion of the body is called uniform motion. In uniform motion the speed of the object is constant.

Non-Uniform motion:- When a body travels unequal distances in equal intervals of time. than the motion of the body is called Non-uniform motion. In Non-uniform motion the speed of object is not constant.

  or

 When a body travels equal distances in unequal intervals of time. than the motion of the body is called Non-uniform motion.

Average speed and average velocity

The total distance traveled by the object in a particular interval of time is called average speed. 

Average speed = Total distance covered / total time taken

∴ Average speed = d1 +d2 + d3 + d4 / t1 + t2 + t3 + t4

Numerical -4

An object travels 16 m in 4 seconds and then another 16m in 2 seconds. What is the average speed of the object.

Solution:- d1 = 16 m        t1 = 4s

                d2 = 16 m        t2 = 2s

total distance = d1 + d2 = 16m + 16m = 32m

total time taken = t1 + t2 = 4s + 2s = 6s

average speed = total distance covered / total time taken

= 32m / 6s = 5.33 m/s

Average velocity

The change in displacement divided by the time intervals in which the displacement occurs is called average velocity. It is the ratio of the total displacement to the total time taken by the object.The average velocity can be negative or positive depending upon the sign of the displacement. The SI unit of the average velocity is m/s.

Average velocity = total displacement / total time

If the velocity is changing but at uniform rate, than the average velocity will be the arithmetic mean of initial velocity and final velocity.

∴ Average velocity = initial velocity + final velocity / 2

Numerical-5

Usha swims in a 90m long pool. She covers 180m in one minute by swimming from one end to other and and back along the same straight path. Find the average speed and average velocity of Usha.

Solution:- Total distance covered by usha in 1 min = 180m

Displacement of usha in 1 min = 0m

∴ Average speed = total distance covered / Total time taken

= 180m /1m = 180m / 60 sec = 3m/s

∴ Average velocity = Total displacement / total time taken

= 0m / 60sec = 0m/sec

Hence, Average speed of usha = 3m/sec   and   Average velocity of usha = 0m/sec

Numerical - 6

An object has moved through a distance. Can it have zero displacement? If yes, support your answer with example.

Ans:- Yes, an object which has moved through a distance can have zero displacement if it comes back to initial position. 

Ex:- If a person jogs in a circular park which is circular and complete one round . His initial and final position is same.

Than his displacement is 0

Numerical-7

A farmre moves along the boundry of a square field of side 10m in 40 seconds. What will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds from his initial point.

Solution:- Rounds covered in 40 seconds = 1

∴Rounds covered in140 seconds = 1/40 ✕ 140

 = 3.5 rounds 

= 3full rounds and 1 half round

In the 3 full rounds displacement = 0 ( because initial and final position are same )

But in next half round displacement =

(AC)² = (AD)² + (DC)²

(AC)² = (10)² + (10)²

(AC)² = 100 + 100

(AC)² = 200

AC = √200

AC = 14.143m

Which of the following is true for displacement?

(a) It cannot be zero

Solution- false

(b) Its magnitude is greater than the distance travelled by the object.

Solution - false

Distinguish between speed and velocity

Speed	Velocity
The rate at which an object covers a certain distance is known as speed.	The rate at which an object changes position in a certain direction
Speed cannot be negative or zero.	It can be negative or zero.
Speed is a scalar quantity.	It is a vector quantity.
Speed = distance / time	Velocity = displacement / time

  

Under what conditions is the magnitude of average velocity of an object equal to its average speed?

Solution:- Only when the object moves along a straight line path.

What does the odometer of an automobile measure?

Solution:- It measures distance travelled by the vehicle.

What does the path of an object look look like when it is in uniform motion.

Ans:- Uniform motion = equal distance covered in equal intervals of time.

∴ speed is constant

As long as speed is constant the path of an object in uniform motion can have any shape.

Numerical-8

During an experiment, a signal from a spaceship reached the ground station in five minutes. What was the distance of the spaceship from the ground station? The signal travels at the speed of light that is

3×10⁸ms^-1  

Solution:- 

Speed = Distance / time

∴ Distance = Speed × time

= 3×10⁸ms^-1  × 5 min

=3×10⁸ms^-1  × 300 sec

=9×10¹⁰ms^-1    

Numerical - 9

A person covers 20m in 5 seconds and then next 20m in 10 seconds along x-axis. Find average speed and average velocity  

Solution:- Solve it by using these formula

Average speed = Total distance / total time

Average velocity = Total displacement / total time

Numerical -10

Shyam goes to the market  from his home which is 50 m away from the shop in 20 sec. On his way back he visited his friends house which is 10 m away from the shop in 10 sec. Find the average speed and average velocity.

Solution:- Solve it by using these formula

Average speed = Total distance / total time

Average velocity = Total displacement / total time

                            = P_f – P_i / t

Numerical - 11

John drove south 12 kms at 4km /hr and then east 15 km at 3km/hr. Determine

1-      Averrage speed of whole journey

2-      Average velocity of whole journey