Welcome to BodhiClasses, your ultimate source for well-structured, curriculum-aligned learning. Below are the NCERT textbook questions from Chapter 5 – “Measurement of Length and Motion“ (Class 6 Science) designed to help students, parents, and teachers reinforce key concepts related to measurement and motion.
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 | centimetre |
| Thickness of a coin | kilometre |
| Length of an eraser | metre |
| Length of school ground | millimetre |
Answer (Correct Matching):
| Length | Appropriate Unit |
|---|---|
| Distance between Delhi and Lucknow | kilometre |
| Thickness of a coin | millimetre |
| Length of an eraser | centimetre |
| Length of school ground | metre |
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
Answers:
(i) True
(ii) True
(iii) False – 1 kilometre = 1000 metres = 100,000 centimetres
3. Which of the following is not a standard unit of measuring length?
(i) millimetre
(ii) centimetre
(iii) kilometre
(iv) handspan
Answer:
(iv) handspan – It is not a standard unit of measurement because it varies from person to person.
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 (Sample Table):
| Measuring Tool | Smallest Unit It Can Measure |
|---|---|
| 15-cm plastic scale | 1 millimetre (mm) |
| Steel measuring tape | 1 millimetre (mm) |
| Tailor’s measuring tape | 1 centimetre (cm) |
| Wooden ruler | 1 millimetre (mm) |
5. Suppose the distance between your school and home is 1.5 km. Express it in metres.
Answer:
1 kilometre = 1000 metres
1.5 km = 1.5 × 1000 = 1500 metres
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:
Take a thread to wrap around the circular base of the bottle. Then measure the thread using a scale.
Example: Circumference of the base = 21 cm (This may vary depending on the object used.)
7. Measure the height of your friend and express it in:
(i) metres
(ii) centimetres
(iii) millimetres
Answer (Example):
Height = 1.45 m
(i) In metres = 1.45 m
(ii) In centimetres = 145 cm
(iii) In millimetres = 1450 mm
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 (Example):
Length of notebook = 21 cm
Length of 1 coin = 2.1 cm
Estimated number of coins = 21 ÷ 2.1 ≈ 10 coins
Verify by placing 10 coins in a line. Measurement will be close to 21 cm.
9. Give two examples each for linear, circular and oscillatory motion.
Answer:
- Linear Motion: Car on a straight road, bullet fired from a gun
- Circular Motion: Blades of a fan, hands of a clock
- Oscillatory Motion: Swing, pendulum of a clock
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.
Answer – Sizes of Objects Around Us
| Size | Objects |
|---|---|
| mm | Thickness of a coin, insect wing, needle |
| cm | Pencil, notebook, spoon |
| m | Door height, table length, blackboard |
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 A to B and E to F – Linear motion
- From B to C and D to E – Circular motion (curved parts)
- From C to D – Oscillatory motion if it goes back and forth
Note: The ball’s overall motion is a combination of linear, circular, and oscillatory motion depending on the segment.
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:
Tasneem should not use paper, cloth, or stretchable rubber because these materials can bend, stretch, or shrink, making them unsuitable for accurate measurement. Steel or plywood are better because they retain their shape.
13. Think, design and develop a card game on conversion of units of length to play with your friends.
Answer (Idea for Game):
Create cards with different length units and values, such as:
- “1 m = ? cm”
- “5000 mm = ? m”
- “1.2 km = ? m”
Each player must match equivalent values to score points. Bonus rounds can include real-life object measurement comparisons. This helps reinforce unit conversion in a fun, competitive way.
