NCERT Solutions Class 6 Science Chapter 5 - Measurement of Length and Motion

Beginning your science journey in Class 6 is quite memorable and a little bit daunting. That is where NCERT Solutions for Chapter 5: Measurement of Length and Motion fit in; to enhance learning and supply some clarity and simplicity as young minds enter the exciting world of science.

Science is a method for making sense of the world: What is the world made of, and why do things happen as they do? It is an empirical method based on observation, experimentation, and evidence. Studying science teaches us how to be curious, question, and think logically; this is applicable outside of the classroom.

The NCERT Solutions for Class 6 Science Chapter 5 helps students build a strong foundation in thinking scientifically and staying curious about how the world works. As these students work through these solutions, they begin to see science as more than a subject; a new way to view the world with wonder, clarity, and logical reasoning.

1.0NCERT Solutions for Class 6 Chapter 5: Measurement of Length and Motion - Download PDF

Download the PDF of NCERT Solutions for Class 6 Science Chapter 5 Measurement of Length and Motion from below:

2.0Key Concepts in Chapter 5: Measurement of Length and Motion

In the NCERT textbook, particularly in Class 6 Science, the chapter “Measurement of Length and Motion” typically introduces students to the fundamental concepts of measuring distances and understanding different types of movement.

• Introduction to Measurement: The chapter begins by explaining the need for accurate measurement in daily life and in scientific observations. It highlights why standard units of measurement are important.
• Units of Length: It introduces the standard international (SI) unit of length, the metre, and its multiples and submultiples (centimetre, millimetre, kilometre). Students learn how to convert between these units.
• Measuring Length: The chapter details various tools used to measure length, such as a ruler, measuring tape, and metre scale. It also covers the correct technique for using these tools, emphasizing the importance of proper placement and avoiding parallax error.
• Motion: This section introduces the concept of motion as a change in position with respect to time. It explains that objects can be at rest or in motion relative to their surroundings.
• Types of Motion: The chapter describes different types of motion with everyday examples:
• • Rectilinear motion: Movement in a straight line (e.g., a car on a straight road).
  • Curvilinear motion: Movement along a curved path (e.g., a thrown ball).
  • Circular motion: Movement along a circular path (e.g., a fan blade).
  • Rotational motion: Movement of an object around its own axis (e.g., a spinning top).
  • Periodic motion: Motion that repeats itself after a fixed interval of time (e.g., a swinging pendulum, the hands of a clock).
  • Oscillatory motion: A type of periodic motion where an object moves back and forth about a mean position (e.g., a swing).
• Measuring Time: While the primary focus is length and motion, the concept of time as a factor in motion is also implicitly or explicitly covered, often in relation to periodic motion.
• Real-life Examples: The chapter uses numerous real-life examples to help students understand the concepts of measurement and motion, making the learning relatable and practical.

Here are some common subtopics covered in this chapter:

• Why do we need to measure?
• Standard units of measurement
• The metre: The SI unit of length
• Multiples and submultiples of the metre (cm, mm, km)
• Measuring length using a ruler and measuring tape
• Correct way to measure length
• What is motion?
• Objects at rest and in motion
• Types of motion:
• • Straight line motion (Rectilinear)
  • Circular motion
  • Rotational motion
  • Periodic motion
  • Oscillatory motion
• Examples of different types of motion in daily life

3.0NCERT Solutions Class 6 Science Chapter 5 - Detailed Solutions

• If the length of a wooden board is 7 m . Express this height in centimetre. Solution Length of wooden board $=7\mathrm{m}$ $1\mathrm{m}=100\mathrm{cm}$ $7\mathrm{m}=7\times 100\mathrm{cm}=700\mathrm{cm}$ Hence, the length of wooden board is 700 cm .
• If the length of your science book is 35 cm .Express this length in metre. Solution Length of science book $=35\mathrm{cm}$ $1\mathrm{m}=100\mathrm{cm}$ $\Rightarrow \frac{1}{100}\mathrm{m}=1\mathrm{cm}\Rightarrow 1\mathrm{cm}=\frac{1}{100}\mathrm{m}$ $\Rightarrow 35\mathrm{cm}=35\times \frac{1}{100}\mathrm{m}=0.35\mathrm{m}$ Hence, the length of science book in metre is 0.35 m .
• If the length of a cloth is 2 metre. Convert this length in milimetre. Solution Length of the cloth = 2 metre $1\mathrm{m}=1000\mathrm{mm}$ $2\mathrm{m}=2\times 1000\mathrm{mm}=2000\mathrm{mm}$ Hence, the length of the cloth is 2000 mm .
• How many metre is in 2000 mm ? Solution $1\mathrm{mm}=\frac{1}{1000}\mathrm{m}$ $2000\mathrm{mm}=2000\times \frac{1}{1000}\mathrm{m}=2\mathrm{m}$ Hence, the answer is 2 metre.
• The distance between Kota and Delhi is 518 km . Express this distance in metre. Solution Distance between Kota to Delhi=518 km. $1\mathrm{km}=1000$ metre $518\mathrm{km}=518\times 1000$ metre $=518000$ metre Hence, distance between Kota to Delhi is 518000 metre.
• If the distance between your school and your home is 4.5 km . Express this in metre. Solution Distance between school and home $=4.5\mathrm{km}$. $1\mathrm{km}=1000$ metre $4.5\mathrm{km}=4.5\times 1000$ metre $=4500$ metre Hence, distance between school and home is 4500 m .
• Convert 25 cm into millimetre. Solution $1\mathrm{cm}=10\mathrm{mm}$ $25\mathrm{cm}=25\times 10\mathrm{mm}=250\mathrm{mm}$. Hence 25 cm is equal to 250 mm .
• If the length of a rice grain is 10 mm . What will be its length in cm . Solution Length of a rice grain $=10\mathrm{mm}$ $1\mathrm{mm}=10\times \frac{1}{10}\mathrm{cm}$. $10\mathrm{mm}=10\times \frac{1}{10}\mathrm{cm}=1\mathrm{cm}$ Hence, length of a rice grain is 1 cm .
• If the height of your friend is 128 cm . Express this height in metre. Solution Height of friend $=128\mathrm{cm}$ $1\mathrm{cm}=\frac{1}{100}$ metre therefore $128\mathrm{cm}=128\times \frac{1}{100}$ metre $=\frac{128}{100}$ metre $=1.28\mathrm{m}$. Hence, the height of friend is 1.28 m .
• Convert 25 km into metre. Solution $1\mathrm{km}=1000\mathrm{m}$. therefore 25 km $=25\times 1000\mathrm{m}$ $=25000\mathrm{m}$ Hence the answer is 25000 m .

NCERT QUESTIONS WITH SOLUTIONS

• Some lengths are given in column I of Table. Some units are given in column II. Match the lengths with the units suitable for measuring those lengths.

Solution $(\mathrm{A}\to \mathrm{q});(\mathrm{B}\to \mathrm{s});(\mathrm{C}\to \mathrm{p});(\mathrm{D}\to \mathrm{r})$

• Read the following statements and mark True (T) or False (F) against each. (i) The motion of a car moving on a straight road is an example of linear motion. (ii) Any object which is changing its position with respect to a reference point with time is said to be in motion. (iii) $1\mathrm{km}=100\mathrm{cm}$ Solution (i) True (ii) True (iii) False
• Which of the following is not a standard unit of measuring length? (i) millimetre (ii) centimetre (iii) kilometre (iv) handspan Solution handspan
• Search for the different scales or measuring tapes at your home and school. Find out the smallest value that can be measured using each of these scales. Record your observations in a tabular form. Solution We can find wooden ruler, plastic ruler, measuring tape, etc. The smallest value that we can record is ' mm '.
• Suppose the distance between your school and home is 1.5 km . Express it in metres. Solution $1.5\mathrm{km}=1000\mathrm{m}+500\mathrm{m}$ $=1500\mathrm{m}$
• Take a tumbler or a bottle. Measure the length of the curved part of the base of glass or bottle and record it. Solution
  
  Length of the curved part of the base of glass bottle $=6.35\mathrm{cm}=2.5$ inch
• Measure the height of your friend and express it in (i) metres (ii) centimetres and (iii) millimetres. Solution Suppose height is 5 feet 2 inches Then, in $\mathrm{mm}=1574.8\mathrm{mm}$ in $\mathrm{cm}=157.48\mathrm{cm}$ in $\mathrm{m}=1.5748\mathrm{m}$
• You are given a coin. Estimate how many coins are required to be placed one after the other lengthwise, without leaving any gap between them, to cover the whole length of the chosen side of a notebook. Verify your estimate by measuring the same side of the notebook and the size of the coin using a $15-\mathrm{cm}$ scale. Solution
  
• Give two examples each of linear, circular and oscillatory motion. Solution Linear motion → (i) Car moving on a straight road. (ii) Airplane flying in the sky Circular motion → (i) Athlete running on a circular track. (ii) Motion of mean around earth. Oscillatory motion → (i) Motion of a swing. (ii) Motion of a pendulum.
• Observe different objects around you. It is easier to express the lengths of some objects in mm , some in cm and some in m . Make a list of three objects in each category and enter them in the table. Table : Sizes of objects around us | Size | Objects | | :--- | :---: | | mm | | | cm | | | m | |

Solution We can select many objects from around such as allen module, floor tiles, clothes line etc.

• A rollercoaster track is made in the shape shown in figure. A ball starts from point A and escape through point F. Identify the types of motion of the ball on the rollercoaster and corresponding portions of the track.
  
  Solution A to B → linear motion B to C to D to E → Circular/curvilinear motion. E to F → linear motion.
• Tasneem wants to make a metre scale by herself. She considers the following materials for it : plywood, paper, cloth, stretchable rubber and steel. Which of these should she not use and why? Solution She must not use stretchable rubber because if any such scale is used, overtime the measurement will be changed or vary.
• Think, design and develope a card game on conversion of units of length to play with your frends.

| Sample Challenge Cards: Card 1: Front: "Convert 1.5 kilometers to meters." Back: "1.5 kilometers = 1500 meters." | | :--- | :--- |

EXERCISE-01

Multiple choice questions

• You are about to express height of K2 Mountain. You will express it in. PLM054 (1) m (2) cm (3) mm (4) km
• The height ten metres is equal toPLM055 (1) 100 cm (2) 100000 mm (3) 1000 cm (4) 1000 dm
• One-thousandth is expressed by which prefix? PLM056 (1) Centi (2) Milli (3) Kilo (4) deci
• The fixed quantity of measurement is called PLM057 (1) Foot (2) Unit (3) Pound (4) Meter
• While measuring length using a metre scale, the position of the eye PLM058 (1) Should be vertically above the zero mark of the scale. (2) Should be vertically above the point where the measurement is to be taken. (3) Should be exactly at the point where the measurement is to be taken. (4) Does not matter as long as the scale is accurate.
• You are about to help your P.T. teacher uses to measure the length of a playground with PLM059
  
  (1) Elastic tape (2) Ruler (3) Tape scale (4) Body parts
• Which type of unit of length will be used to find thickness of a coin? PLM060 (1) km (2) metre (3) millimetre (4) centimetre
• Which device can be used to measure length of curved line? PLM061 (1) Metre scale (2) Elastic tape (3) Thread and ruler (4) None of these
• One of the early measure of distance was PLM062 (1) litre (2) kilogram (3) hand span (4) gram
• Which of the following statements is not valid for both rotational and circular motion? PLM063 (1) Rotation about an axis passing through the body. (2) Body moves and changes position with respect to time. (3) Body stays in the same place with respect to time. (4) To and fro motion of a body about its mean position.
• Which of these is dissimilar or different from the others? PLM064 (1) A car taking turn on a curved road (2) Motion of a swing (3) Motion of needle end of a sewing machine (4) Motion of an engine piston
• An example of rotational motion is PLM065 (1)The Moon revolving around the Earth. (2)The Earth rotating about its own axis. (3) The Earth revolving around the Sun. (4) Tshe bob of a swinging pendulum.
• In which of the following motion, there is no change in the direction of movement of the body? PLM066 (1) Rotational motion (2) Rectilinear motion (3) Periodic motion (4) All of the above
• Which part of the moving cycle undergoes rotational motion? PLM067
  
  (1) Only A (2) A and B (3) A and C (4) B and D
• What kind of motion does a pendulum have? PLM068
  
  (1) Periodic motion (2) Rectilinear motion (3) Rotational motion (4) Non-periodic motion
• Motion of which of the following is not periodic? PLM069 (1) Beating of a drum by a drummer (2) Rotation of the Earth on its axis (3)Revolution of Moon around the Earth (4) Movement of a pendulum
• The motion of the arms of soldiers taking part in march past is PLM070 (1) Circular motion (2) Periodic motion (3) Rotational motion (4) Rectilinear motion
• An example of rectilinear motion is (1) Apple falling from a tree PLM071 (2) Motion of a car on road (3) A spinning top (4) Both (1) and (2)
• Motion of the Earth is PLM072 (1) Circular motion (2) Periodic motion (3) Rotational motion (4) All the three types
• Motion of a screw while going into the wood is an example of PLM073
  
  (1) Rectilinear and circular motion (2) Rotation and revolution (3) Rotation and spin motion (4) Rotational and rectilinear motion
• The motion exhibited by the ball rolling down an inclined plane is : PLM074
  
  (1) Rotational and circular (2) Rotational and periodic (3) Linear and rotational (4) Uniform motion
• What kind of motion is executed by a pendulum of a wall clock? PLM075 (1) Rectilinear motion (2) Periodic motion (3) Circular motion (4) (1) and (2) Both
• Windmill shows $\_\_\_\_$ motion. PLM076
  
  (1) Rotational (2) Circular (3) Linear (4) None of these
• Which of the following does not involve combination of motion? PLM077 (1) A car (2) A bicycle (3) Spinning top (4) Rolling ball
• Earliest mode of transport on water was PLM078 (1) Aeroplane (2) Yacht (3) Logs tied together (4) Bullock cart

True or false

• We can understand a measurement even without a unit. PLM079
• The standard unit of length is centimetre in metric system. PLM080
• A standard unit is always a fixed measure of a physical quantity. PLM081
• The choice of a length-measuring device depends upon the type of measurement to be made. PLM082
• Kilometre is used for measuring small distances. PLM083
• We can trust on the measurements taken by use our senses and body parts. PLM084
• A body is said to be in motion only if its position changes with time. PLM085
• The motion of the seconds hand of a clock is rotational. PLM086
• The motion of the ball in a game of football is linear. PLM087
• The motion of the Moon around the Earth can be considered as a circular motion. PLM088

1.Match the column PLM089

2.Match the Column

Fill in the blanks

• The determination of the size or magnitude of something is called $\_\_\_\_$ . PLM092
• Five kilometre is $\_\_\_\_$ m. PLM093
• An object is said to be in motion if its $\_\_\_\_$ changes with time. PLM094
• In rectilinear motion objects move along $\_\_\_\_$ path. PLM095
• Motion of a child on a swing is $\_\_\_\_$ . PLM096
• An object in $\_\_\_\_$ motion moves about an axis. PLM097
• Motion of wheel of a bicycle is $\_\_\_\_$ . PLM098
• Any type of motion that repeat itself after equal intervals of time is called $\_\_\_\_$ . PLM099
• To measure the diameter of a tree, you can use $\_\_\_\_$ . PLM100
• Rotation of the Earth about its axis is a $\_\_\_\_$ motion but it is $\_\_\_\_$ an oscillatory motion. PLM101

1.Crossword PLM102

ANSWER KEY

Multiple choice questions

True or false

• False
• False
• True
• True
• False
• False
• True
• True
• False
• True

Match the column

• (1) → (b), (2) $\to (\mathrm{c}),(3)\to (\mathrm{a}),(4)\to (\mathrm{d})$
• (1) → (d), (2) $\to (\mathrm{c}),(3)\to (\mathrm{a}),(4)\to (\mathrm{b})$

Fill in the blanks

• Measurement
• 5000
• Position
• Straight
• Oscillatory motion6. Rotational
• Rotational motion + Linear motion
• Periodic motion
• Measuring tape
• Periodic; not Crossword puzzle
  

EXERCISE-02

Very short answers type questions

• Define measurement. PLM103
• Define unit. PLM104
• What is the SI unit of length? PLM105
• Give three example where length can be measured in metre. PLM106
• Which type of metre scale is used by the tailor to measure length? PLM107
• Name the measuring device you can use to measure the girth of a tree. PLM108
• Arrange following in increasing order : $1\mathrm{km},5\mathrm{cm},10\mathrm{mm},4\mathrm{m}$ PLM109
• Give two examples of periodic motion.
• What kind of movement does the Earth have about its axis? PLM110
• Define circular motion of an object with suitable example. PLM111
• Define rotatory motion with a suitable example? PLM112
• Define the term rectilinear motion. PLM113
• What do you understand by term periodic motion? PLM114
• Classify the following as circular, periodic or rectilinear motion : PLM116 Swing, Speed boat racing, 100 m race, Rocking chair, The Moon revolving around the Earth.
• Give one example of modes of transport used on land, water and air. PLM117 Short answer type questions
• What is the need for standard units of measurement? PLM118
• Why could you not use an elastic measuring tape to measure distance? What would be some of the problems you would meet in telling someone about a distance you measured with an elastic tape? PLM119
• Why a cubit can't be used as standard unit of length? PLM120
• How can one measure the length of a curved line? PLM121
• What precautions should be taken while measuring length with a ruler? PLM122
• How did people measure length in early times? PLM123
• Write the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched on. PLM124
• Can an object have more than one type of motion? If yes, give two examples. PLM125
• What is periodic motion? Give any two examples. PLM126
• What is the difference between motion of a falling stone and motion of a stone tied to a thread and whirled with hand? PLM127

Long answer type questions

• Explain, how will you measure the length of a book using a perfect scale. What should you do if the scale is broken at its zero end? Make figure and give an example. PLM128
• Explain in brief the types of motion and give one example of each. PLM129

Numerical Problems

• Arrange the following lengths in their increasing magnitude: PLM130 1 metre, 1 centimetre, 1 kilometre, 1 millimetre.
• Convert: PLM131 (a) 250 m to cm (b) 120 m to km (c) 521 mm to cm (d) 178 km to m (e) 812 cm to m .
• Give the metric prefix for each value : PLM132 (a) 1000 (b) 0.01
• The height of a person is 2.25 m . Express it into cm and mm . PLM133
• The distance between Radha's home and her friend's home is 4862 m . Express this distance into km. PLM134

ANSWER KEY

Numerical problems

• $1\mathrm{mm},1\mathrm{cm},1\mathrm{m},1\mathrm{km}$
• (a) 25000 cm (b) 0.12 km (c) 52.1 cm (d) 178000 m (e) 8.12 m
• (a) Kilo (b) Centi
• $225\mathrm{cm};2250\mathrm{mm}$
• 4.862 km

4.0Key Features of NCERT Solutions Class 6 Science Chapter 5: Measurement of Length and Motion

• A Good Foundation in STSE: The solutions provide clear explanations and organized responses that help students to develop a strong understanding of the fundamental principles and concepts related to motion and measurement in Class 6. 
• Increased Conceptual Understanding: The solutions not only provide answers, but explain the why and how around scientific phenomena in Class 6 Science Chapter 5 lessons which helps to enhance students' understanding of the concepts.
• Increased Ability to Solve Problems: The more students apply the solutions, the more they develop a systematic way of working towards a solution, which is a necessary skill in STSE. 
• Greater Exam Preparedness: It ensures students have the chance to practice questions (multiple choice, short answer, long answer, case study) in a controlled and, failure-free environment which helps: a) prepare them to solve exam questions successfully, b) provides them with the knowledge and ability to succeed.
• Increased Confidence: Whenever students can understand and answer according to their textbook questions correctly, it increases their confidence in the subject.