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

These NCERT Solutions for Class 6 Science Chapter 10 Motion and Measurement of Distances Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

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

### Class 6 Science Chapter 10 Motion and Measurement of Distances Textbook Exercise Questions and Answers

Question 1.
Give two examples each of modes of transport used on land, water and air.
Mode of transport on land: Buses, railways
Mode of transport in water: Boats, ships Modes of transport in air: Airplanes, gas balloons.

Question 2.
Fill in the blanks:
a. One metre is ……………… cm.
b. Five kilometre is ……………… m.
c. Motion of a child on a swing is ………………
d. Motion of the needle of a sewing machine is ………………
e. Motion of wheel of a bicycle is ………………
a. 100
b. 5000
c. oscillatory motion
d. periodic motion
e. circular motion

Question 3.
Why can a pace or a footstep not be used as a standard unit of length?
The pace or a footstep has different lengths for different persons. So they cannot be used as a standard unit of length.

Question 4.
Arrange the following lengths in their increasing magnitude:
1 metre, 1 centimetre, 1 kilometre, 1 millimetre.
1 millimetre > 1 centimetre > 1 metre > 1 kilometre Question 5.
The height of a person is 1,65 m. Express it into cm and mm.
a. 165 cm, as one metre = 100 cm
= 1.65 × 100 cm = 165 cm
b. 1.65 × 100 × 10 mm = 1650 mm

Question 6.
The distance between Radha’s home and her school is 3250 m. Express this distance into km.
As one km = 1000 m
So, 3250 m = 3250/1000 km = 3.250 km

Question 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?
Length of needle = 33.1 cm – 3.0 cm = 30.1 cm.

Question 8.
Write the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched on.
The motion of a bicycle and a ceiling fan are in circular motion. Thus both show similar motion. But the ceiling fan moves without changing its position while the bicycle moves with changing its position with time. This shows dissimilarities between two motions. Question 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?
Elastic material will not give accurate measurement because its stretches in length and reduces in size when not stretched. While telling the measurement taken with an elastic tape, we have to tell whether the tape was stretched and by how much, which is very difficult.

Question 10.
Give two examples of periodic motion.
The motion of pendulum of clock and the motion of child on a swing are the two examples of periodic motion.

NCERT Extended Learning Activities And Projects

Question 1.
Draw a map of your classroom. Roll a ball on the floor. In your map mark the points where the ball started and where it stopped. Show’ also the path it moved along. Did the ball move along a straight line?
Hint: The ball will move in a straight line unless a force is applied on it.

Question 2.
Using string and a scale, let each student measure the length of his/her foot. Prepare a bar graph of the foot length measurements that have been obtained for the whole class.
Hint: Do it yourself.

Activity 1

Objective: To measure the length of a table using hand span.
Materials Required: A table.
Procedure:

• Stretch your hand for measuring the length of the table.
• Move it along the length of the table.
• Count the number of hand spans you move along the length.
• Repeat the process thrice. Observations: The number of hand spans is …………… each time.
Conclusion: The length of the table is …………… hand spans.

Measurement of Length: The SI unit of length is metre (m). While measuring length, following points should be kept in mind:
i. The scale should be placed along the length of object.
ii. The scale should be placed exactly in a straight line.
iii. Reading should be taken from the zero mark of the scale and not from its edge. Activity 2

Objective: To measure the length of a curved line using a thread.
Procedure:

• Draw a curved line on a sheet of paper.
• Place the paper on a smooth surface.
• Mark the beginning point of the line as point A and end point as point B.
• Take the thread and place it along the line keeping it touch with the help of your thumb or forefinger.
• Put the thread on the line from point A to point B.
• Now, stretch the thread along a metre scale and measure the length between the two marks. Conclusion: The length of the curved line is ………………. cm.

Rest: Rest is when a body does not change its position over time.
Motion: Motion is when an object changes its position over time. There are various types of motion:
i. Linear Motion: Linear motion is the motion when a body moves along a straight line path. Eg., a car moving on straight road.
ii. Circular Motion: Circular motion is the motion when a body moves along a circular path. Eg., motion of the hands of a clock. iii. Rotational Motion: Rotational motion is the motion when an object turns about a fixed axis. Eg., rotation of a top and the earth.
iv. Periodic Motion: Periodic motion is the motion which repeats itself after regular intervals of time. Eg, motion of a pendulum. Activity 3

Objective: To classify the following objects at rest or in motion.
House, table, clock, a school bag, a stone lying on the ground, a flying bird, second’s hand of the clock, a moving train, a child on the swing, heart beat in a healthy person and a spin ball in cricket.
Observations :

• Objects at rest: House, table, clock, a school bag, a stone lying on the ground.
• Objects in motion: Flying bird, second’s hand of clock, moving train, child on a swing, heartbeat in a healthy person, spin ball in cricket.

Conclusion:

• The objects at rest do not change their position with respect to time.
• The objects in motion change their position with the time.

### Class 6 Science Chapter 10 Motion and Measurement of Distances Additional Important Questions and Answers

Question 1.
In prehistoric times, which animals were used as means transport?
Horses, camels, oxen.

Question 2.
Name two water transports and two air transports.
Boats and ships are the means of water transport. Airplanes and hot air balloons are the means of air transport.

Question 3.
What is cubit?
Cubit is a unit of measurement which includes the distance from elbow to the tip of the middle finger. Question 4.
What is the standard unit of measuring length?
Metre is the standard unit of measuring length.

Question 5.
What is the use of a ruler?
Ruler is used to measure lengths of straight objects.

Question 6.
When is an object said to be in rest?
When an object does not change its position with respect to time and the observer the object is said to be in rest.

Question 7.
When is an object said to be in motion?
When the object changes its position with respect to time and the observer, the object is said to be in motion.

Question 8.
Which motion takes place in fixed direction?
Linear motion.

Question 9.
Define periodic motion.
The motion which repeats itself after regular intervals of time is called periodic motion. Question 10.
Name the types of motion which a body undergoes during rolling.
Translatory and rotatory motion.

Question 11.
Why do people need transport?
To move from one place to another.

Question 12.
Which invention made a great change in the modes of transport?
Invention of wheel.

Question 13.
Were one cubit or one pace accurate unit of measurement?
No. Question 14.
Which measuring device is required to measure the chest of a person?
Measuring tape.

Question 15.
Which type of motion can be seen in the ball rolling on ground?
Linear motion.

Question 1.
Which units of measurement were derived from the length of some parts of human body?
A pace or a footstep, a cubit that is the distance from the elbow to the tip of the middle finger, hand span and width of the fingers.

Question 2.
Define standard unit of measurement.
A unit of measurement which has a fixed value and does not change from person to person or place to place is called a standard unit of measurement.

Question 3.
Which precautions should be taken while measuring the length with a metre scale?

• The initial point of distance must coincide with the zero reading of metre scale.
• The eye should be kept in line with the point of measurement.
• The scale should be perfectly horizontal. Question 4.
What is rotational motion? Give two examples of rotational motion.
When an object turns about a fixed axis, it is called rotational motion. A spinning top and rotation of the earth on its axis are the examples of rotational motion.

Question 5.
Which types of motion are shown by a bicycle?
Suppose a bicycle is moving on a straight road. The wheel of bicycle is rotating on its axis and also moving forward in a straight line path. So, a bicycle on a straight road has two types of motion: rotational motion as well as rectilinear motion.

Question 6.
Give a method to measure the thickness of one rupee coin.
Collect ten one rupee coins and stack them. Measure the height of the stacked coins in millimetres. Tick the thickness of ten coins. Divide this thickness by 10. You will get the average thickness of one coin. Question 7.
How does merry-go-round show two types of motion?
Merry go round as a whole shows rotatory motion as it turns on its own axle. But the outer part of merry go round on which the children sit shows circular motion. Thus, the child sitting on a merry go round will exhibit circular motion.

Question 8.
How can a measured length be expressed?
A measured length can be expressed by

• a number describing the numerical value.
• the unit in which that quantity is measured.

Question 9.
What are the advantages of using a measuring scale?

• The scale can be easily taken from one place to another,
• The scale does not change during measurements.

Question 1.
What is the standard unit of measurement? Why is it required?
A unit of measurement which has a fixed value and which does not change from person to person or place to place, is called a standard unit of measurement. It is required to make our judgments more reliable and accurate. For proper dealing, measurement should be same for everybody. Thus, there should be uniformity in measurement. For the sake of uniformity we need a common set of units of measurements. Question 2.
What is the proper way of using a measuring scale?
a. The scale should be placed along the length to be measured. The scale should be placed very close to the object to be measured.

b. Keep your eye in line with the point of measurement. If the eye is not in line with the point of measurement, the measured length will be either shorter or longer than the actual length.

c. Do not start measurement from the worn out or damaged end of the scale. If the zero end of the scale is damaged, start measurement from some other mark of the scale. Then the actual length of the object is equal to the difference between the readings at the two points.

Question 3.
Define motion. Explain the different types of motion.
When an object changes its position with respect to time and observer, it is said to be in motion. The different types of motion are:
a. Rectilinear motion: When a body moves along a straight line, it is called rectilinear motion. Motion of train on straight track and motion of a falling stone are the examples of rectilinear motion.

b. Circular motion: When a body moves along a circular path, it is called circular motion. Movement of the earth around the sun and movement of the moon around the earth the examples of circular motion.

c. Rotational motion: When an object turns about a fixed axis, it is called rotational motion. Spinning of top and spinning of the earth on its axis are the examples of rotational motion.

d. Periodic motion: The motion which repeats itself after regular intervals of time, is called periodic motion. Motion of second’s hand of clock and the revolutions of earth around the sun are the examples of periodic motion.

Picture-Based Questions

Question 1.
a. Identify the device shown below. b. What type of motion does it exhibit?
c. Give one more example of such motion.
a. Pendulum
b. Periodic motion
c. Motion of a child on a swing is periodic. Question 2.
a. Identify the devices A and B. b. What are they used for?
c. What is the SI unit of the quantity measured by these devices?