Chapter 5 Measurement of Length and Motion Class 6 Science Curiosity NCERT Solutions
Chapter 5 Measurement of Length and Motion NCERT Solutions Class 6 Science
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Question 1. Some lengths are given in Column I of Table 5.5. Some units are given in Column II. Match the lengths with the units suitable for measuring those lengths.
|
Column I |
Column II |
|
Distance between Delhi and Lucknow |
kilometre |
|
Thickness of a coin |
millimetre |
|
Length of an eraser |
centimetre |
|
Length of school ground |
metre |
Question 2. Read the following statements and mark True (T) or False (F) against each.
(i) The motion of a car moving on a straight road is an example of linear motion. [ ]
(ii) Any object which is changing its position with respect to a reference point with time is said to be in motion. [ ]
(iii) 1 km = 100 cm [ ]
Answer
(i) True (T)
(ii) True (T)
(iii) False (F)
Question 3. Which of the following is not a standard unit of measuring length?
(i) millimetre
(ii) centimetre
(iii) kilometre
(iv) handspan
Answer
(iv) handspan
Question 4. Search for the different scales or measuring tapes at your home and school. Find out the smallest value that can be measured using each of these scales. Record your observations in a tabular form.
Answer
|
Type of Scale, Tape, Device |
Smallest Value of Measurement |
|
15 cm Scale |
1 mm |
|
Flexible Tape |
1 mm, 1 inch |
|
Long Tape Roll |
1 cm, 1 inch |
|
Vernier Calliper (from School Lab) |
0.1 mm |
|
Screw Gauge (from School Lab) |
0.01 mm |
Question 5. Suppose the distance between your school and home is 1.5 km. Express it in metres.
Answer
We know that 1 km = 1000 m
∵ 1 km = 1000 metres
∴ 1.5 km = 1.5 × 1000
= 1500 metres
The distance between my school and home is 1500 m.
Question 6. Take a tumbler or a bottle. Measure the length of the curved part of the base of glass or bottle and record it.
Answer
We will use a flexible measuring tape or a piece of thread to measure the length of the curved part of the base of glass or bottle.
First, we will place the tape or thread around the round base and after that we will measure the lenght of tape or thread on the measuring instrument.
Question 7. Measure the height of your friend and express it in:
(i) metres
(ii) centimetres and
(iii) millimetres.
Answer
We know that,
1m = 100 cm and,
1cm = 10mm
So, if the height of the friend is 1.55 metres.
(i) Metres = 1.55 m
(ii) Centimetres = 155 cm
(iii) Millimetres = 1550 mm
Question 8. You are given a coin. Estimate how many coins are required to be placed one after the other lengthwise, without leaving any gap between them, to cover the whole length of the chosen side of a notebook. Verify your estimate by measuring the same side of the notebook and the size of the coin using a 15-cm scale.
Answer
We will place the coin on the side of the notebook and then count the number of coins.
For verification, measure the actual length of the side of the notebook and the diameter of one coin.
Divide the length of the notebook by the diameter of the coin to find the exact number of the coin needed.
Diameter of the coin = 2cm
Length of the notebook = 20 cm
Number of coins to be placed on the book to cover the whole length = 20/2 = 10 cm
Question 9. Give two examples each for linear, circular and oscillatory motion.
Answer
- Linear motion: A car moving on a straight road, an object dropped from height.
- Circular motion: Motion of ceiling fan, movement of satellite around earth.
- Oscillatory motion: A swinging pendulum, vibrating strings of guitar.
Question 10. Observe different objects around you. It is easier to express the lengths of some objects in mm, some in cm and some in m. Make a list of three objects in each category and enter them in the Table 5.6.
Answer
|
Size |
Objects |
|
mm |
(i) thickness of a coin (ii) diameter of a small screw (iii) thickness of wire |
|
cm |
(i) length of a pencil (ii) height of a water bottle (iii) length of a smartphone |
|
m |
(i) height of a building (ii) width of a playground (iii) height of a man |
Question 11. A rollercoaster track is made in the shape shown in Fig. 5.19. A ball starts from point A and escapes through point F. Identify the types of motion of the ball on the rollercoaster and corresponding portions of the track.
Answer
From point A to B: Linear motion
From point B to C: Circular motion
From point C to D: Circular motion
From point D to E: Circular motion
From point E to F: Linear motion
Question 12. Tasneem wants to make a metre scale by herself. She considers the following materials for it—plywood, paper, cloth, stretchable rubber and steel. Which of these should she not use and why?
Answer
Tanseem shouldn’t use the following materials:
- Stretchable rubber: It can be stretched easily and cannot give precise measurements.
- Cloth: It can be stretched and wrinkled which make it unfit for measurement.
- Paper: It is very fragile and can be deform and tear easily.
Plywood and steel are more suitable as they maintain consistent lengths.
Question 13. Think, design and develop a card game on conversion of units of length to play with your friends.
Answer
Create cards with different lengths and corresponding units (mm, cm, m, km). Each card can have a length in one unit and players must match it to its equivalent in another unit.
For example, a card with “100 cm” would match with “1 m”.