Motion and Measurement of Distances is Chapter 10 taken from JKBOSE Class 6 Science. You will get short notes and question answers in the chapter Motion and Measurement of Distances in this post. The previous post was about Chapter 9 The Living Organisms and their Surroundings Question Answers. Let’s begin:
Motion and Measurement of Distances Class 6th Question Answers
Overview of Chapter
- STORY OF TRANSPORT
- HOW FAR HAVE YOU TRAVELLED? HOW WIDE IS THIS DESK?
- SOME MEASUREMENTS
- STANDARD UNITS OF MEASUREMENTS
- CORRECT MEASUREMENT OF LENGTH
- MEASURING THE LENGTH OF A CURVED LINE
- MOVING THINGS AROUND US
- TYPES OF MOTION
STORY OF TRANSPORT: In ancient times, there was no means of transport. People used to move only on foot and carry goods either on their backs or using animals. Boats were used for transport along water routes. Ancient boats were simple logs of wood having cavities but later on, they learnt to make boats.
The invention of the wheel and the domestication of animals brought a great change in the mode of transport. Now people used to make carts using wheels which were pulled by domestic animals.
Till the early 19th century people were dependent on animals’ power to transport them from one place to another but the invention of the internal combustion engine was the beginning of a new era in the development of means of transport which now have so many modern means of transport.
HOW FAR HAVE YOU TRAVELLED? HOW WIDE IS THIS DESK? When we move from one place to another, we can measure how far we have reached by determining the length between the initial point and the endpoint. We can measure the width of the table by using a small length of string and marking two points on it.
SOME MEASUREMENTS: Measuring something means comparing an unknown physical quantity with a known physical quantity having a fixed value. This known fixed quantity is called a unit. The result of a measurement is expressed in two parts. One part is a number. The other part is the unit of measurement. If we use the hand span or length of the foot as a unit of measurement, the results could be different because of the difference in length of hand and foot from person to person. Therefore, some standard units of measurement are needed
STANDARD UNITS OF MEASUREMENTS: For the sake of uniformity, scientists all over the world have accepted a set of standard units of measurement. The system of units now used is known as the International System of Units (SI units). The SI unit of length is a metre.
CORRECT MEASUREMENT OF LENGTH: Correct measurement of any is very necessary. There are many devices like centimetre scale, metre scale, and metre tape. For small measurements, such as the length of your pencil, you can use a 15 cm scale from your geometry box. In measuring a length, we need to take care of the following:
- Place the scale in contact with the object along its length.
- In some scales, the ends may be broken. You may not be able to see the zero mark. In such cases, you can use any other full mark of the scale, say, 1.0 cm and then subtract the reading of this mark from the final reading.
- The correct position of the eye is also important for taking measurements. Your eye must be exactly in front of the point where the measurement is to be taken.
MEASURING THE LENGTH OF A CURVED LINE: We cannot measure the length of a curved line directly by using a metre scale. We can use a thread to measure the length of a curved line.
MOVING THINGS AROUND US: There are so many things around us. Some of them are stationary while others are moving. The moving things are things said to be in motion. When a body or an object changes its position with respect to time, then it is said to be in motion.
TYPES OF MOTION: Some important types of motion are:
- Rectilinear motion
- Circular motion
- Periodic motion
- Rotational motion
Motion and Measurement of Distances Question Answers
- Give two examples of each, of the modes of transport used on land, water and air.
Ans. Modes of transport used on land are buses and trucks
Modes of transport used on the water are boat and ship.
Modes of transport used in the air are aeroplanes and helicopters.
- Fill in the blanks:
(i) One metre is ______ cm.
(ii) Five kilometres is ______ m.
(iii) Motion of a child on a swing is ______.
(iv) Motion of the needle of a sewing machine is ______.
(v) Motion of the wheel of a bicycle is ______.
(vi) The 1/1000 part of meter is called ______. (JKBOSE)
(vii) 1000 times the length of a meter is called ______. (JKBOSE)
(i) One metre is 100 cm.
(ii) Five kilometres is 5000 m.
(iii) Motion of a child on a swing is periodic motion.
(iv) Motion of the needle of a sewing machine is periodic motion.
(v) Motion of the wheel of a bicycle is circular motion.
(vi) The 1/1000 part of the meter is called a millimetre. (JKBOSE)
(vii) 1000 times the length of a meter is called a kilometre. (JKBOSE)
3. Why can a pace or a footstep not be used as a standard unit of length?
Ans. We cannot use pace or a footstep as a standard unit of length because the size of the foot and the footsteps is not the same for every individual. So, the measurement will not be the same for every individual. Since standard units are the same all over the world, we cannot use pace or footstep as standard units of length.
4. Arrange the following lengths in their increasing magnitude:
1 metre, 1 centimetre, 1 kilometre,1 millimetre.
Ans. Since 1 km = 1000 m
1 m = 100 cm
1 cm = 10 mm.
The increasing order of the given units is
1 millimetre < 1 centimetre < 1 metre < 1 kilometre.
5. The height of a person is 1.65 m. Express it into cm and mm.
Ans. Height of a person = 1.65 m.
We know that
1 metre (m) = 100 centimetre (cm)
1 metre (m) = 1000 millimetre (mm)
So, the height of a person in centimetres (cm) = 1.65 × 100 = 165 cm
Height of a person in millimetres (mm) = 1.65 × 1000 = 1650 mm
6. The distance between Radha’s home and her school is 3250 m. Express this distance into km.
- 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. The actual reading of the scale starts at 0 cm but in this case, the reading at the start is 3.0. So, we have to subtract 3.0 cm from the final reading to obtain the length of the needle.
\ Length of the needle is 33.1 cm – 3.0 cm = 30.1 cm.
- Write the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched on.
Ans. Similarities between the motion of a bicycle and a fan.
- Both bicycle and fan show rotational motion on a fixed axis.
- The particles of both show circular motion except the particle at the centre.
Differences between the motion of a bicycle and a fan.
- The bicycle changes its position while having circular motion while a fan does not change its position.
- The bicycle shows a rectilinear motion but a fan does not show a rectilinear motion
- Why could you not use an elastic measuring tape to measure distance? What would be some of the problems you would meet in telling someone about a distance you measured with elastic tape?
Ans. We cannot use an elastic measuring tape to measure distances because elastic substances have a property of elasticity. It is the property of a substance due to which it gets stretched or compressed upon applying force. So, measurements taken using elastic tape can never be correct.
The major problem that we face in telling someone about a distance we measured using an elastic tape is that we cannot tell anyone the exact measurement of distance because we could be confident of the measured distance.
- Give two examples of periodic motion.
Ans. The two examples of rectilinear motion are:
- Motion of earth around the sun.
- Movement of hands of a watch.
- You are sitting in a moving bus and looking out? Are you in a state of motion or rest? Explain. (JKBOSE)
Ans. While sitting in a bus we are in motion as the bus is in motion. So, we are in motion with respect to the road, trees, and passing places. But at the same time, we are at rest with respect to other passengers and seats of the bus.
- Giving at least two examples, define the terms
- Rectilinear motion
- Rotatory motion
- Oscillatory motion
- Periodic motion
- Rectilinear Motion: Motion along a straight line is termed rectilinear motion. For example, bullets fired from a gun, marching past soldiers, the motion of free-falling objects etc.
- Rotatory Motion: When an object turns or spins about a fixed axis, it is called rotatory motion. For example, the motion of the spinning top, spinning of the earth on its axis, turning of bicycle wheel etc.
- Oscillatory Motion: When a body moves about its mean position crossing it again and again, it is termed oscillatory motion. For example, the motion of a child on a swing, moving of a clock pendulum etc.
- Periodic Motion: The motion which repeats itself after regular intervals of time is known as periodic motion. For example, the motion of the minute or second hand of a wristwatch, the revolution of the earth around the sun.
This is all about Motion and Measurement of Distances Class 6th Question Answers. Hope it has helped. Do share your views about this post.