The Measurement of Length and Motion Class 6 notes are designed for CBSE Class 6 science students. It was arranged such that they would make the process of learning distances and motion easier for the students of NCERT class 6 science chapter 5. The syllabus for class 6 science has been thoroughly updated, and this article will show you how to measure lengths precisely with the help of various tools and further examine the different ways of moving of objects.
The NCERT class 6 science chapter 5 notes have made an attempt to simplify the material by breaking it down into small and easily digestible sections. So, no matter if you’re studying for your exams or just want to get a clearer picture of the topics, these notes will greatly assist you with their lucid explanations and generous supply of examples.
Table of Contents
Download Measurement of Length and Motion Class 6 Notes PDF | NCERT Solutions for Class 6 Science Chapter 5
Measurement of Length and Motion Class 6 Notes | NCERT Class 6 Science Chapter 5
What is the meaning of measurement?
Measurement is the process of determining the size or magnitude of something by comparing it to a standard, known quantity. This comparison results in a value that includes a number and a unit, which can be used to describe physical quantities like length, weight, or temperature.
How do we measure?
Measurement can be done in various ways by using different tools. We measure length with a suitable tool like a 15 cm ruler for small objects, a measuring tape for curves or larger items, or a meter scale for general use.
Common terms for measurement?
- ANGULA: For small measurements that can be covered with joined fingers.
- HANDSPAN/BALISHTH: Measurement from tip of the thumb to tip of the little finger when palm is stretched.
- CUBIT: Length of arm from elbow to the tip of the finger.
- YARD: Measurement from chin to the tip of the fingers of a full stretched arm.
- STRIDES: Steps taken by a person while walking.
- FOOT: Measurements of a person’s feet.
Standard units: (Measurement of length and motion class 6)
What is the need of Standard Unit?
Using local units or non-symmetrical units create confusion and problem in understanding for others. To bring symmetry in units that can be used all over the world.
Which system of unit is followed?
The system of units now used is known as the “International System of Units” or SI units. The SI unit of length is meter denoted by “m”.
Would it be convenient to use the unit metre to measure larger lengths, such as the length of a railway track between two cities, or to measure smaller lengths, such as the thickness of a page of a book? page-83
No, it would not be convenient to use the unit meter for measuring very large or very small lengths. measuring very large or very small lengths. For larger lengths (like the length of a railway track between two cities), it is better to use kilometers (km), because the distance would be too large to express in meters. For smaller lengths (like the thickness of a page), it is better to use millimeters (mm) or centimeters (cm), because the value in meters would be too small and inconvenient.
meter (m) is the SI unit we all know that. But if we add some prefix before meter (m) then we can find different SI unit for measurement. like:
- KILOmeter
- HECTOmeter
- DECAmeter
- Meter
- DECImeter
- CENTImeter
- MILLImeter
Conversion of units: (Measurement of length and motion class 6)
Bigger unit to smaller:
- 1 km = 1000 m
- 1 m = 100 cm
- 1 cm = 10 mm
Example: 7 km = mm?
We all know that 1 km – 1000 cm. So,
7 km= 700 * 1000 * 1000 * 100 * 10 mm
Smaller unit to bigger:
- 1 m = 1/1000 km
- 1 cm = 1/100 m
- 1 mm = 1/10 cm.
Example: 550 mm = cm?
We all know that 1 mm = 1/10 cm. So, 550 mm = 550/10 cm = 55cm.
Correct Way of Measuring: (NCERT class 6 science chapter 5)
Till this section, we learn about the SI units, values, etc. But we need to know the correct way of measuring. For this, there are three major things that we will have to notice while measuring.
1. Correct scale:
There are different types of scales available for measuring different types of objects. Choose the appropriate scale according to what needs to be measured.
2. There are different types of scales available for measuring different types of objects. Choose the appropriate scale according to what needs to be measured.
Place the scale in contact with the object along its length.
3. Correct position of eye for reading:
The positions of your eyes should be exactly perpendicular to the place of reading on the scale.
How to do measurement with the broken scale?
Answer: If the ends of the scale are broken or the zero marking is not clear, it can still be used for measurement. With such scale, use any other full mark of the scale. Then you must subtract the reading of this mark from the reading at the other end.
Writing the measurement: (NCERT class 6 science chapter 5)
- Length is always measured in 2 pairs.
- 1st is the number followed by the unit. E.g. – 3 cm, 4 m, 50 km
Measuring the length of curved lines:
In such cases of curved lines, measurements can be made with the help of a flexible measuring tape or by using thread.
Describing positions:
When distance is started with respect to a fixed object or point, then this point is called a reference point.
Let’s Draw:
3 cm horizontal line B, 5 cm vertical line C, line joining the end of line B & C.
For my case the diagram looks like this. But I am sure that in your case the diagram can look different.
Now try using a reference point.
From reference point A
- 3 cm horizontal line
- 5 cm vertical line
- line joining the end of line B & C
So, you can see that if we use any reference point, then the diagram will be the same for everyone.
Significance of reference point:
When the object is changing position with time with respect to the reference point, we consider the object is moving or in motion.
or
When the object is not changing position with time with respect to the reference point, we consider object is not moving or at rest.
Moving things – let’s explore: page-90
| OBJECTS IN MOTION | JUSTIFICATION | OBJECT AT REST | JUSTIFICATION |
|---|---|---|---|
| Cow grazing in the field | Because the cow is changing his position with respect to the time. | Tree | Not changing its position |
| Soldiers marchpast | Soldiers are moving from one point to another point. | Mountain | Not changing its position |
| Flowing river | water is flowing one place to another. | Parked car | Still in garage. not changing its position with respect to the time |
| Car on highway | changing position with respect to the time. | Car at traffic light | still at one place |
| Kids on see-saw | Bench at the park | still at one place |
Moving things:
Reference points decide whether the motion was there or not.
- Motion is relative to the reference point.
- The reference point is important in deciding whether an object is at rest or in motion.
Like, for a passenger inside the moving train, the next seat passenger is at rest if taking himself as a reference point.
But, if the passenger takes reference point as some stationary object outside the train, then everyone, including the train is in motion.
Types of motion:
There are majorly 3 types of motions that happen.
1. Linear motion:
When an object moves along a straight line, its motion is called linear motion.
2. Circular motion:
When an object moves along a circular path, its motion is called circular motion.
3. Oscillatory motion:
When an object moves to and fro about some fixed position, its motion is called oscillatory motion.
4. Periodic motion:
In circulatory or oscillatory motion the object is coming back to its initial point after fixed interval of time then the motion will be called periodic in nature as well.
Activity 5.7: page – 95
See this image carefully and fill the below table. do this at your home and let me know in the comment section.
Measurement of Length and Motion Class 6 Notes | Question Answer Solved
Let us enhance our learning:
1. Some lengths are given in Column I of Table 5.5. Some units are given in Column II. Match the lengths with the units suitable for measuring those lengths.
Answer:
| Column I | Column II |
|---|---|
| Distance between Delhi and Lucknow | Kilometre |
| Thickness of a coin | Millimetre |
| Length of an eraser | Centimetre |
| Length of school ground | Metre |
2. 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. [ True ]
- (ii) Any object which is changing its position with respect to a reference point with time is said to be in motion. [ True ]
- (iii) 1 km = 100 cm [ False ]
3. Which of the following is not a standard unit of measuring length?
(i) millimetre (ii) centimetre (iii) kilometre (iv) handspan
Answer: (iv) Handspan
4. 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.
Answer: Here’s how we can record our observations for the activity:
| Place | Type of scale | Material | Smallest value |
|---|---|---|---|
| Home | Steel ruler (15 cm or 30 cm) | Metal | 1 mm (0.1 cm) |
| Home | Tailor’s measuring tape (150 cm) | Flexible plastic or cloth | 1 mm (0.1 cm) |
| School | Wooden metre scale | Wood | 1 mm (0.1 cm) |
5. Suppose the distance between your school and home is 1.5 km. Express it in metres.
Answer:
1 km = 1000 m. So, 1.5 km = 1.5 X 1000 = 1500 m
The distance between your school and home is 1500 metres.
6. Take a tumbler or a bottle. Measure the length of the curved part of the base of glass or bottle and record it.
Answer:
You can use these methods for measure the length of the curved part of the base of glass or bottle:
- Take a measuring tape or a string.
- Wrap it once around the curved bottom of the tumbler or bottle.
- If using a string, mark the point where it completes one circle.
- Measure the length of the string using a ruler.
7. Measure the height of your friend and express it in (i) metres (ii) centimetres and (iii) millimetres.
Answer:
You can measure your friends hright using a measuring tape or string. if Suppose your friend’s height = 1.45 metres.
- Metres(m): 1.45 metres
- Centimetres (cm): 1m=100cm -> 1.45×100=145cm
- Millimetres (mm): 1m=1000mm -> 1.45×1000=1450 mm
8. 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-cm scale.
Answer:
Look at the notebook’s longer side and guess how many coins (kept in a straight line, touching each other) might cover that length. Suppose Length of notebook (longer side) = 21 cm and Diameter of one coin = 2.1 cm.
So, Number of coins = length of notebook / diameter of one coin = 21/2.1 = 10
9. Give two examples each for linear, circular and oscillatory motion.
Answer:
- Linear motion: (i) A car moving on a straight road and (ii) a ball rolling on the floor in a straight path.
- Circular motion: (i) The hands of a clock moving around the dial and (ii) a ceiling fan rotating about its axis.
- Oscillatory motion: (i) A swinging pendulum and (ii) the vibration of a tuning fork.
10. 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 5.6.
Answer:
| Size | Objects |
|---|---|
| 3600 mm | mobile phone |
| 52 cm | TV |
| 2 m | Bike |
11. A rollercoaster track is made in the shape shown in Fig. 5.19. A ball starts from point A and escapes through point F. Identify the types of motion of the ball on the rollercoaster and corresponding portions of the track.
Answer:
The ball will travel point A to B in Linear motion. Point B to C in Oscillatory motion. Point C to D also Oscillatory motion. Point D to E also Oscillatory motion and point E to F Linear motion.
12. 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?
Answer:
Stretchable rubber should not be use for create a metre scale. Because Stretchable rubber changes its length when pulled or stretched.