# NCERT Solutions Class 6 Science Chapter 10

NCERT Solutions for Class 6 Science Chapter 10

The topic Motion and Measurement of Distances Class 6 will no longer be difficult for students if they refer to the NCERT Solutions for Class 6 Science Chapter 10 that have detailed answers to all the textbook questions.

The NCERT Solutions for Class 6 Science Chapter 10 include questions and answers on different modes of transportation used for going from one place to another, measurement and SI units of measurement and different types of motion including motion in a straight line, circular motion, rectilinear motion and periodic motion. This study material is prepared by subject matter experts as per the latest guidelines by the CBSE.

## NCERT Solutions for Class 6 Science Chapter 10– Motion and Measurement of Distances

The important topics covered under Motion and Measurement of Distances Class 6 are as follows:

1. 10.1 – Story of Transport
2. 10.2 – How Wide is This Desk?
3. 10.3 – Some Measurements
4. 10.4 – Standard Unit of Measurements
5. 10.5 – Correct Measurement of Length
6. 10.6 – Measuring the Length of a Curved Line
7. 10.7 – Moving Things Around Us
8. 10.8 –  Types of Motion

Some important points to remember in this chapter are:

• Standard measures refer to those measures that are the same throughout the world.
• The 12th general conference on weight and measures (that was held in October 1960) adopted the International system of units. The International System of units is a set of units that were established to maintain uniformity of units throughout the world.
• A metre is the standard unit of length.
• One metre is divided into 100 equal divisions, called centimetres. Further, one centimetre has ten equal divisions of millimetres. Hence we may conclude that:
• 1 metre = 100 centimetres
• 1 centimetre = 10 millimetres
• A kilometre is another unit of length that is used for measuring distances that are so large that a metre cannot be a convenient unit for measuring such large distances. Thus, a larger scale of measurement for long distances is defined where 1 kilometre= 1000 metres.

### 10.1 Story of Transport

Transport was a problem for humans in early days. Because of the absence of vehicles, humans had to travel on foot. Later, the discovery of wheels brought a revolution in transportation. Humans found out that they can use wheels to travel long distances in a shorter time. As a result, they could do more work during the time left.

However, the wheels were not a proper mode of transportation on the water. People found out that dead wooden planks float on the water. So they started making vessels from wooden planks, which led to the creation of boats. After that, people started travelling through boats on the water.

### 10.2 How far have you travelled and how wide is this desk?

The NCERT Class 6 Science Chapter 10 discusses the importance of distance. Before we start travelling, we need to know how much distance has to be covered. If it is a short-distance travel, it can be covered on foot. However, a vehicle is needed for long-distance travel.

To measure the distance, it should be expressed in the terms of length. If we are measuring long distances, we need to use larger scales.

Another way to measure the distance travelled is by multiplying the circumference of the wheel to the number of rotations it has to perform to cover the entire distance.

### 10.3 Some Measurements

Measurement is a means for comparing an unknown quantity with the features of a known one. Such a comparison is usually depicted in two parts – number and its unit.

The units are defined for different entities, and it is followed worldwide. The measurements do not change from person to person.

### 10.4 Standard Units of Measurement

All the countries follow standard units of measurements. However, some countries have regional units also. For example, people used to measure small distances with their fingers in India. However, the standard units of length followed universally is metre. Similarly, there are different units for measurable quantities like degrees for temperature and grams for weight.

### 10.5 Correct Measurement of Length

As mentioned earlier, length is measured universally in terms of metres. However, for smaller lengths, the unit of centimetre is used and for larger lengths, kilometres and miles are used. The correct way for measuring length is to measure it in a straight line.

Chapter 10 mentions the correct way to measure length.

### 10.7 Moving Things Around Us

If you look around, you will notice that there are many things at rest and in motion around us. For example, a chair is at rest while a butterfly is in motion. You can make a list of such objects and monitor their state of rest or motion. Having done so, you will find out that you can define motion in terms of a change in the position of an object.

### 10.8 Types of Motion

This section of the solution explains to you the different types of motion. The different bodies around you depict these motions, for example, a train moves in a straight line, swings or pendulums exhibit oscillating motion, the ceiling fan exhibits circular motion, musical instruments show vibrational motion and so on. Chapter 10 explains all these motions in detail.

### Key Features of NCERT Solutions for Class 6 Science Chapter 10

The key features of NCERT Solutions for Class 6 Science Chapter 10 are as follows:

• The solutions are prepared by subject matter experts while keeping the CBSE guidelines in mind.
• The solutions have answers to all the questions given in the NCERT Science Class 6 textbook.
• The answers are written in simple language and explained with the help of examples and diagrams, wherever required.

Q.1 Give two examples each, of modes of transport used on land, water and air

Ans-

Modes of transport used on land: Cars and trains

Modes of transport used on water: Ships and boats

Modes of transport used in air: Airplanes and helicopters

Q.2 Fill in the blanks:

(i) One metre is ______________ cm.

(ii) Five kilometre is ______________ m.

(iii)Motion of a child on a swing is ______________.

(iv) Motion of the needle of a sewing machine is ______________.

(v) Motion of wheel of a bicycle is______________.

Ans-

(i) One metre is 100 cm.

Explanation: There are 100 cm in 1 m.

(ii) Five kilometres is 5000 m.

Explanation: There are 1000 m in 1 km.

So, 5 km = 5 × 1000 m = 5000 m

(iii) Motion of a child on a swing is periodic.

Explanation: At a certain time interval, the motion of a swing repeats itself. Hence, it is an example of periodic motion.

(iv) Motion of the needle of a sewing machine is periodic.

Explanation: The needle of a sewing machine moves up and down frequently in a certain time interval. So, it is an example of periodic motion.

(v) Motion of the wheel of a bicycle is circular.

Explanation: The wheel of a bicycle rotates about a fixed point as the bicycle moves. Thus, it is an example of circular motion.

Q.3 Why can a pace or a footstep not be used as a standard unit of length?

Ans-

The size of the foot is not same of each person. When footsteps of two people are used to measure the length, the two distances may not be equal. Therefore, footstep is not a constant quantity and cannot be used as a standard unit of length.

Q.4 Arrange the following lengths in their increasing magnitude:

Ans-

1 metre, 1 centimetre, 1 kilometre,1 millimetre.

On converting all the given measures in millimetres (mm), we get

1 cm = 10 mm

1 m = 100 cm = 1000 mm

1 km = 1000 m = 100000 cm = 1000000 mm

So, the lengths in increasing order of magnitude can be written as,

1 millimetre < 1 centimetre < 1 metre < 1 kilometre

Q.5 The height of a person is 1.65 m. Express this in cm and mm.

Ans-

Given, height of the person = 1.65 m

As, 100 cm = 1 m

So, height of the person in cm = 1.65 × 100 cm = 165 cm

Also, 1000 mm = 1 m

So, height of the person in mm = 1.65 × 1000 cm = 1650 mm

Q.6 The distance between Radha’s home and her school is 3250 m. Express this distance into km.

Ans-

$Given, the distance between Radha’s home and her school = 3250 m As 1 km = 1000 m or 1 m = 1 1000 km Converting 3250 m into km, we get ⇒ 3250 m = 3250× 1 1000 km = 3.25 km$

Q.7 While measuring the length of a knitting needle, the reading of the scale at one end is 3.0 cm and at the other end is 33.1 cm. What is the length of the needle?

Ans-

Given, reading at one end = 3.0 cm

reading at the other end = 33.1 cm

The length of the knitting needle can be calculated by subtracting 33.1 cm by 3.0 cm.

length of the knitting needle = 33.1 cm – 3.0 cm = 30.1 cm

Hence, the length of the knitting needle would be 30.1 cm.

Q.8 Write the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched on.

Ans-

Similarities: The blades of the fan and the wheels of the bicycle are attached at a fixed point. Secondly, both have circular motion about their respective fixed points.

Differences: The blades of the fan have circular motion while the bicycle has linear motion. Secondly, the motion of the blades of a fan is periodic while the motion of a bicycle is rectilinear motion.

Q.9 Why would you not like to use a measuring tape made of an elastic material like rubber to measure distance? What would be some of the problems you would meet in telling someone about a distance you measured with such a tape?

Ans-

An elastic measuring tape is not a suitable measuring scale because it can be stretched. In this case, the measured length would not be correct. If you measure the length of an object twice using an elastic tape, then you may get different values of the same length.

Q.10 Give two examples of periodic motion.

Ans-

1. In a simple pendulum, the bob repeats its motion at a certain time interval. This motion is known as periodic motion.
2. The motion of a swing repeats its motion at a certain time interval. Thus, a girl sitting on a swing has periodic motion.

1. Discuss the various modes of transport used on land, water and air with the help of examples.

The various modes of transport used on land, water and air discussed in Chapter 10 are –

• On land – bus, train, car
• On the water – boat, ship, etc.
• In Air – aeroplane, helicopter, etc.

2. Discuss the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched on.

A similarity between them is that a circular motion is shown by both the blades of a fan and the wheels of a bicycle.

A difference between them is that a bicycle moves in a rectilinear motion while a fan does not move in a rectilinear motion.

3. What are the different units of length?

Although length is measured in many local units, there are some universal units for it as well. The standard unit of length is metre. For smaller distances, millimetres and centimetres are used and for longer distances, kilometres and miles are used. These units are discussed in the chapter on Motion and Measurement of Distances in detail. You can learn more about them from there if you want.

4. How can one measure the length of a curved line?

NCERT Class 6 Science Chapter 10 explains the process of measuring the length of a curved line in detail. As per it, a string is required for this task. For measuring such length, you need to place the thread parallel to the line’s curve. On the string, you then need to mark the beginning and finish of the line. Then, using a ruler, you can measure the distance between these two spots to get the measurement of the length of the curved line.