class 6 science chapter 10

  Class 6 ncert chapter 10

 Motion and Measurement of Distances

This chapter all about motion and movement. Different modes of transport are used to go from one place to another. And also way to measure motion.

Class 6 science chapter 10 notes

What is distance -

 distance is a length that we travel,
 distance is a length between two objects,
 distance also can be length or breath of       something.

Measurement:-

 In ancient times, people use length of a foot, the width of a finger, the distance of a step as unit of measurement.

This cause confusion because width of finger,or length of foot different person to person and a need to develop a uniform system of measurement arose.

Now, we use International System of Unit (SI unit).This is accepted all over the world.

Metre is the SI unit of length. Unit is the fixed quantity and do not change place to place.

Standard Units of Measurement

To avoid confusion, scientists all over the world have accepted a set of standard Units of measurement called SI units.
There are some measurement units:-
1m    = 100cm
1cm  = 10mm
1km  = 1000m

MOTION

Motion seems to be some kind of a change in the position of an object with time.
In other words- motion is the movement of object from one place to another with time is known as motion.

Types of Motion

1. Rectilinear motion :-

 Motion in a straight line is called rectilinear motion. Example- vehicle on a straight road.

2. Circular motion:- 

Motion in circular path. In circular motion an object moves such that its distance from a fixed points remains the same . Examples - circular motion of a fan and clock.

3. Periodic motion :- 

Motion that repeats itself after some period of time, is called periodic motion. Examples- periodic motion of a pendulum, motion of child on a swing.

4. Rotational motion :- 

Rotating motion of a object from its fixed axis known as rotational motion. Example- rotational movement of earth.

Class 6 science solutions

Chapter 10 - Exercise Solution

Q1. Give two example each of modes of transport used on land, water and air.

Ans:-

Land - Car, train.
Water - Ship, boat.
Air - Aeroplane, helicopter.

Q2. Fill in the blanks:-
i). 1 metre is ____________ cm.
ii. 5 kilometre is ___________m.
iii). Motion of a child on a swing is _______.
iv). Motion of the needle of sewing                         machine is __________.
v). Motion of wheel of a bicycle is_________.
Ans:-
i) 100
ii) 5000
iii) Periodic motion
iv) Periodic motion
v) Circular motion

Q3. Why can a pace or a footstep not be used as a standard unit of length?
Ans:-
 Because a pase or a footstep of each and every person does not same. Therefore each time the measurement will be different.

Q4. Arrange the following lengths in their increasing magnitude :-
1 metre, 1 centimetre, 1 kilometre, 1 millimetre.
Ans:-
Ascending ( Increasing) order
1 millimetre<1 centimetre<1 metre<1kilometre

Q5. The height of a person is 1.65 metre. Express it into centimetre and millimetre.
Ans:-
      i) 1m = 100cm.
          1.65 × 100 = 165cm
      ii) 1m = 1000mm
          1.65 × 1000 = 1650mm

Q6. The distance between Radha's home and her school is 3250. Express this distance into kilometre.
Ans:-
   1 Km = 1000m
So, 1m = 1/1000 km
   3250m = 3250/1000= 3.250 km

Q7. 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:-
To find length of the needle, we have to two subtract two reading:-
  The length of knitting needle is-
   33.1 - 3.0 = 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:-
Similarity- wheels of a bicycle and fan both are moving in circular motion around a fixed point.
Differences - motion of bicycle is showing linear motion because it is moving forward,other hand ceiling fan is not.

Q9. Why could you not use an elastic measuring tape to measure distance? what would be some of the problems you would made in telling someone about a distance you measure with an elastic tape?
Ans:- 
When we measure length with the elastic tape, we will get different values of the same distance each time due to its stretching behaviour

Q10. Give two example of periodic motion.
Ans:-
a. Motion of a pendulum.
b. Motion of earth around the sun.