Science In Everyday Life Solutions for Class 6 Science Chapter 11 Measurement And Motion are provided here with simple step-by-step explanations. These solutions for Measurement And Motion are extremely popular among Class 6 students for Science Measurement And Motion Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Science In Everyday Life Book of Class 6 Science Chapter 11 are provided here for you for free. You will also love the ad-free experience on Meritnationâ€™s Science In Everyday Life Solutions. All Science In Everyday Life Solutions for class Class 6 Science are prepared by experts and are 100% accurate.

#### Question 1:

Write two examples for each of the following.
1. Rectilinear motion ...........................................................................................................
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2. Curvilinear motion ..........................................................................................................
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3. Rotational motion ...........................................................................................................
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4. Periodic motion ..............................................................................................................
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5. Non-periodic motion .....................................................................................................
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#### Answer:

1. Rectilinear motion
(i) A train moving on a straight track.
(ii) A car moving on a straight road.

2. Curvilinear motion
(i) A car taking a turn.
(ii) A child going down a slide.

3. Rotational motion
(i) Motion of blades of a rotating fan.
(ii) Motion of blades of a windmill.

4. Periodic motion
(i) To and fro motion of a pendulum.
(ii) Motion of hands of a clock.

5. Non-periodic motion
(i) A car moving on a road.
(ii) Birds gliding across the sky.

#### Question 1:

An example of a standard unit of measurement is
(a) hand span
(b) pace
(c) yard
(d) inch

#### Answer:

(d) inch
Because it does not vary from person to person and place to place.

#### Question 2:

Metre is the SI unit of
(a) mass
(b) volume
(c) length
(d) weight

#### Answer:

(c) length
The SI unit of length is metre (m).

2500 m equals
(a) 25 inches
(b) 25 cm
(c) 2.5 km
(d) 2.5 cm

#### Answer:

(c) 2.5 km

Since 1000 m =1 km
∴ 2500 m =

#### Question 4:

An object is said to be in motion if its position (with respect to another object)
(a) changes with time
(b) does not change with time
(c) does not change
(d) is the same as before

#### Answer:

(a) changes with time
A body is said to be in motion if its position with respect to the another object changes with time.

#### Question 5:

A car moving on a straight road is in
(a) curvilinear motion
(b) rectilinear motion
(c) periodic motion
(d) rotational motion

#### Answer:

(b) rectilinear motion
It is because the movement of an object in a straight line is rectilinear.

#### Question 1:

Fill in the blanks with the correct words.
1. ..................... (Kilometer/Cubit) is a non-standard unit of length.
2. The distance of an object from one end to the other is called ..................... (length/kilometre).
3. When a body is in translational motion, all its parts move ..................... (equal/unequal) distances in a given time.
4. The rotation of Earth on its axis is ..................... (translational/rotational) motion.
5. A type of motion that repeats itself after equal intervals of time is called ..................... (curvilinear/periodic) motion.

#### Answer:

1. Cubit is a non-standard unit of length.
2. The distance of an object from one end to the other is called length.
3. When a body is in translational motion, all its parts move equal distances in a given time.
4. The rotation of Earth on its axis is rotational motion.
5. A type of motion that repeats itself after equal intervals of time is called periodic motion.

#### Question 1:

Why do we need standard units of measurements?

#### Answer:

The units, in which our different body parts are measured, are not reliable because the length of our body parts varies from person to person. Therefore, we need standard units of measurement.

#### Question 2:

Give one advantage of using Sl units.

#### Answer:

The International System of Units or SI units are the modern form of the metric system.
Advantage: Scientists of different countries can communicate their results easily to one another.

#### Question 3:

Write a short note on the relevance of estimation.

#### Answer:

The 'idea of how much' is estimation. It is not necessary to make accurate measurements in all cases.
Example: A rough idea of the quantity of each ingredient is enough to cook a meal. Estimation skills are very useful in our life. In such type of calculations, we can find a number that is close enough to the right answer.
Let us assume we want to plant a row of flowers.
Given:
The length of the row = 58.3 cm = 60 cm (approx)
The distance between two adjacent flowers = 6 cm
∴ Total number of flowers planted in a row = 60/6 = 10 (approx)

Therefore, estimation is relevant for our everyday life.

#### Question 4:

Give two differences between rectilinear and curvilinear motions.

#### Answer:

 Rectilinear Motion Curvilinear Motion When an object in translational motion moves in a straight line, it is said to be in rectilinear motion. Example: Motion of a car on a straight road. When an object in translational motion moves along a curved path, it is said to be in curvilinear motion. Example: Motion of a car taking a turn.

#### Question 5:

Give one similarity between rectilinear and curvilinear motions.

#### Answer:

Both the rectilinear motion and curvilinear motion are types of translational motion. In this type of motion, all parts of an object move the same distance in a given time.

#### Question 1:

Usha wants to buy a dupatta that is 250 cm long. The shopkeeper wants her to give the measurement in metres. Can you help her?

#### Answer:

We know that,
100 cm = 1 m
or 1 cm = $\frac{1}{100}\mathrm{m}$
∴ 250 cm =
Thus, Usha should tell the shopkeeper that she needs a dupatta of 2.50 metre in length.

#### Question 2:

Maya's Physics text book is 11 mm thick and her Maths text book is 1 cm thick. Which text book is thicker?

#### Answer:

Given:
Thickness of Physics textbook = 11 mm
Thickness of Math textbook = 1 cm
To compare the thickness of books, the measurements should be in the same unit.
We know that,
1 cm = 10 mm
∴ Thickness of Math textbook = 10 mm
Thus, Physics textbook is thicker.

#### Question 3:

Amar lives in a hostel which is 20,00,000 m away from his house. Calculate the distance in km.

#### Answer:

It is given that:
Distance between Amar's hostel and his house = 20,00,000 m
We know that:
1,000 m = 1 km
or 1 m = $\frac{1}{1000}\mathrm{km}$
∴ 20,00,000 m =
Thus, Amar lives in a hostel that is 2,000 km away from his house.

#### Question 1:

Discuss with examples how people measured length in ancient times.

#### Answer:

In ancient times, people used different body parts to measure length.
Examples:
Hand span: It is the distance between the tip of the thumb and the tip of the little finger of a fully stretched hand.
Cubit: It is the distance between the tip of the middle finger and the elbow.
Fathom: It is the length of the outstretched arms.
However, these units were not reliable, so people realised the need for standard units.

#### Question 2:

Discuss the precautions that one should take while measuring length with a ruler.

#### Answer:

The following precautions should be taken while measuring length with a ruler:

1. The ruler should be kept along the length of the object carefully.
2. Measurement should only be started from a mark that is fully clear. Example: If you measure from 3-cm mark to the 7-cm mark, the length is 4 cm (7 − 3 = 4 cm).
3. Eyes should be exactly above the point where the measurement is to be taken, otherwise you might get faulty or inaccurate readings.

#### Question 3:

Explain how one can measure length of a curved line using a string.

#### Answer:

One can measure the length of a curved line using a string and a ruler.
In this method, the following steps are taken:

• Take a non-stretchable string and tie a knot at one of its ends.
• Place the knotted end of the thread at one end of the curved line.
• Hold the string steadily with your fingers and stretch it along the curved line until you reach the other end.
• Make a mark on the thread where it reaches the other end.
• Place the string along a ruler and measure the length between the knot and the marked point.
Thus, the length of a curved line is measured using a string.

#### Question 4:

Describe the different types of motion with examples.

#### Answer:

The different types of motion are explained with examples as given below:
1. Translational motion
A motion in which all parts of an object move equal distance in a given time is called translational motion.
Types of translational motion:
(i) Rectilinear motion
(ii) Curvilinear motion
When an object in translational motion moves in a straight line, it is said to be in rectilinear motion.
Example: Motion of a car on a straight road.
When an object in translational motion moves along a curved path, it is said to be in curvilinear motion.
Example: Motion of a car taking a turn.

2. Rotational motion
When an object moves about an axis and different parts of it move by unequal distances in a given interval of time, it is said to be in rotational motion.
Example: Motion of blades of a windmill.

3. Periodic motion
A motion that repeats itself after equal intervals of time is called periodic motion.
Example: The to and fro motion of a pendulum.

4. Non-periodic motion
A motion that does not repeat itself at regular intervals of time is called non-periodic motion.
Example: Birds gliding across the sky.

#### Question 2:

Define the following.
1. Length
2. Motion
3. Periodic motion
4. Rotational motion

#### Answer:

1. Length
The distance of something from one end to the other is called length.

2. Motion
An object is said to be in motion if its position (with respect to another object) changes with time.

3. Periodic motion
A motion that repeats itself after equal intervals of time is called periodic motion.

4. Rotational motion
When an object moves about an axis and different parts of it move by different distances in a given interval of time, it is said to be in rotational motion.

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