Complete notes and important questions for NCERT Class 6 Science Chapter 10 – Motion and Measurement of Distances. Covers history of transport, standard units, methods of measurement, types of motion (rectilinear, circular, periodic), errors in measurement, and solved Q&A. Ideal for CBSE Class 6 revision and exam preparation.
Table of Contents
📘 Class 6 Science Chapter 10 NOTES
Class 6 Science Chapter 10:
Motion and Measurement of Distances
⭐ 1. History of Transport
Early humans traveled by:
- Walking
- Riding animals
Later inventions:
- Wheel
- Bullock carts
- Boats
- Cars, trains, airplanes, rockets
Travel has become faster and easier with time.
⭐ 2. What Is Measurement?
Measurement = comparison of an unknown quantity with a known fixed unit.
Example: measuring length using scale.
Standard Units
To avoid confusion, we use fixed units like:
- Metre (m) → standard unit of length
- Kilometre (km)
- Centimetre (cm)
- Millimetre (mm)
⭐ 3. Units of Length
1 km = 1000 m
1 m = 100 cm
1 cm = 10 mm
⭐ 4. Measuring Length Correctly
Rules for using a scale:
- Place the ruler straight along the object
- Start reading from 0 mark
- Keep your eye straight above the scale to avoid parallax error
- Use scales that are not broken
⭐ 5. Motion
When an object changes its position with time, it is said to be in motion.
Types of Motion:
A. Rectilinear Motion
Movement in a straight line
Example: car on a straight road
B. Circular Motion
Movement in a circular path
Example: rotating fan, hands of a clock
C. Periodic Motion
Repeated motion after fixed intervals
Example: pendulum, swings
D. Random Motion
Motion without a fixed path
Example: insects flying
⭐ 6. Objects at Rest
When an object does not move, it is in a state of rest.
Example: a book on the table.
⭐ 7. Distance
The total length of the path covered by an object.
⭐ 8. Measuring Large Distances
Used in:
- Maps
- Road distances
Measured in kilometres.
📘 IMPORTANT QUESTIONS & ANSWERS
Class 6 Science Chapter 10
✅ 1 Mark Questions
1. What is the SI unit of length?
Metre.
2. Name a device used to measure length.
Ruler / measuring tape.
3. What is rectilinear motion?
Motion along a straight line.
4. 1 metre = ______ cm?
100 cm.
5. What type of motion does the hands of a clock show?
Circular motion.
✅ 2 Mark Questions
6. Why are standard units important?
To avoid confusion and ensure uniform measurement worldwide.
7. How can errors occur while measuring length?
If the eye is not placed straight above the scale (parallax error) or if the scale is broken.
8. What is periodic motion? Give one example.
Motion repeated at regular intervals.
Example: pendulum.
✅ 3 Mark Questions
9. Explain the difference between motion and rest.
- Motion: object changes position
- Rest: object remains in the same position
Example: running car (motion), parked car (rest)
10. Describe circular, rectilinear, and periodic motions with examples.
- Rectilinear: straight line → train
- Circular: circular path → bicycle wheel
- Periodic: repeated → swing
11. What precautions should be taken while measuring length?
- Start from zero mark
- Place scale along the object
- Eye should be straight above markings
- Avoid broken scales
✅ 5 Mark Questions
12. Describe the different types of motions with three examples each.
Rectilinear Motion
- Car moving straight
- Falling ball
- Train on straight track
Circular Motion
- Earth revolving around Sun
- Ceiling fan
- Wheel of bicycle
Periodic Motion
- Pendulum
- Heartbeat
- Hands of a clock (seconds hand)
13. Explain the importance of measurement. What would happen if there were no standard units?
- Measurements make daily life activities possible
- Allow fair buying/selling
- Help in construction, science, transport
Without standard units: - Confusion
- Inaccurate measurements
- Communication problems
⭐ HOTS Questions
Class 6 Science Chapter 10
14. Why do we use kilometres to measure distance between cities?
Because the distance is very large; using metres would be inconvenient.
15. If a child walks in a zig-zag path, what kind of motion is it?
Random motion.
16. Why does a broken scale cause measurement errors?
Because the zero mark may not be visible, giving incorrect readings.