Extra 20 important long questions and answers from the chapter:10 "Motion and Measurement of Distances" for Class 6 Science (CBSE):-
1. Why do we need a standard unit of measurement?
Answer: We need a standard unit of measurement because:
Uniformity:
Different people measure differently using handspan, footstep, etc., leading to variations.
Accuracy:
Standard units provide accurate results in scientific experiments and daily life.
Worldwide Acceptance:
SI units (International System of Units) are used globally for consistency.
Avoiding Confusion:
Different countries had their own units, which created confusion.
Easy Conversion:
Standard units allow easy conversion from one unit to another (e.g., meters to kilometers).
Reliable Measurements:
They help in trade, construction, and science where precision is needed.
2. Describe the different types of motion with examples.
Answer: There are four main types of motion:
Rectilinear Motion:
Motion in a straight line (e.g., a car moving on a straight road).
Circular Motion:
Motion in a circular path around a fixed point (e.g., the hands of a clock).
Rotational Motion:
Motion around an axis (e.g., a spinning top).
Periodic Motion:
Motion that repeats after a fixed time (e.g., a pendulum swinging).
3. What are the different methods used to measure length?
Answer: The following methods are used:
Using a Ruler:
For measuring small lengths like a notebook or a pen.
Measuring Tape:
Used for longer objects like height, walls, or land.
Thread Method:
Used to measure curved objects.
Odometer:
Used in vehicles to measure long distances.
Vernier
Callipers
:
For precise small measurements.
Digital Measurement Tools:
Advanced tools like laser-based measurement devices.
4. How do you measure the length of a curved line?
Answer: The steps to measure a curved line are:
Take a thread
and place it along the curved line carefully.
Mark the starting and ending points
on the thread.
Straighten the thread
and place it along a ruler.
Read the measurement
from the ruler in
centimetres
or
millimetres
.
Record the value
to ensure accuracy.
Repeat the process
to confirm the result.
5. What precautions should be taken while measuring length?
Answer: To ensure accurate measurement:
Use a proper measuring instrument
(scale, measuring tape, etc.).
Place the ruler correctly
along the object.
Start from the zero mark
on the ruler.
Keep your eyes perpendicular
to the scale to avoid errors.
Avoid broken or bent scales
as they may give incorrect values.
Measure multiple times
to confirm accuracy.
6. What is rectilinear motion? Give examples.
Answer: Rectilinear motion is motion in a straight line.
Examples:
A car moving on a straight road.
A train moving on railway tracks.
A falling stone.
A bullet fired from a gun.
An athlete running on a straight track.
A lift moving up or down.
7. What is circular motion? Give examples.
Answer: Circular motion is motion around a fixed point in a circular path.
Examples:
The hands of a clock.
A fan’s blades spinning.
The Earth’s revolution around the Sun.
A car moving in a roundabout.
A child riding a merry-go-round.
A satellite orbiting the Earth.
8. What is rotational motion? Give examples.
Answer: Rotational motion occurs when an object spins around a fixed axis.
Examples:
A spinning top.
A turning wheel of a bicycle.
The Earth rotating on its axis.
A potter’s wheel.
The movement of a turbine in a power plant.
A turning doorknob.
9. What is periodic motion? Give examples.
Answer: Periodic motion is motion that repeats at regular intervals.
Examples:
A pendulum swinging in a clock.
The heartbeat of a person.
The movement of a seesaw.
The oscillation of a guitar string.
A planet revolving around the Sun.
The vibration of a tuning fork.
10. What is the difference between rectilinear and circular motion?
Answer:
|
Feature |
Rectilinear Motion |
Circular Motion |
|---|---|---|
|
Path |
Straight line |
Circular path |
|
Example |
Car moving on a road |
Fan blades rotating |
|
Direction |
Fixed direction |
Continuously changing direction |
|
Force required |
Less force required |
Centripetal force required |
|
Type of movement |
Linear displacement |
Rotational displacement |
11. What is the importance of motion in our daily life?
Answer:
Walking and running involve motion.
Vehicles move from one place to another due to motion.
Machines work based on different types of motion.
Earth’s rotation and revolution create day and night.
Fans and clocks function due to motion.
Motion enables sports, transportation, and other daily activities.
12. How do we measure the length of an object using a ruler?
Answer:
Place the ruler along the object's length.
Ensure the object aligns with the
zero mark
of the ruler.
Keep your
eyes perpendicular
to the ruler to avoid parallax error.
Read the marking at the other end of the object.
Record the length in
centimetres
or
millimetres
.
Repeat the process to confirm the measurement.
13. What are the advantages of using SI units?
Answer:
Universally accepted
and used worldwide.
Easy conversion
between different units.
Standardized for accuracy
in science and industry.
Eliminates confusion
from using non-standard units.
Applicable for all measurements
(length, time, weight, etc.).
Reliable for scientific experiments
and engineering.
14. What are the disadvantages of using non-standard units of measurement?
Answer:
Inconsistency
– Different people measure differently.
Not accurate
– Handspan, cubit, etc., vary in size.
Cannot be used in science
– No exact values.
Not universally accepted
– Different countries had different traditional units.
Difficult to convert
into precise values.
Not suitable for precise work
like engineering and construction.
15. How can we measure large distances, like the distance between two cities?
Answer:
Large distances are measured in
kilometers (km)
instead of meters.
Odometers
in vehicles help measure the distance
travelled
.
Maps and GPS systems
are used for accurate distance calculation.
Surveyors use
measuring chains or electronic devices
for precise measurement.
Astronomical distances
(like Earth to Moon) are measured in light-years or astronomical units.
Large-scale distances require
scientific and technological methods
for accuracy.
16. How do we convert units of length?
Answer:
Metric system conversions:
1 km = 1000 m
1 m = 100 cm
1 cm = 10 mm
To convert
larger to smaller units, multiply
(e.g., 3 km = 3000 m).
To convert
smaller to larger units, divide
(e.g., 500 cm = 5 m).
Use
conversion tables
to simplify unit changes.
Standard units make calculations easier
in science and engineering.
Avoid using
non-standard units
like footstep or handspan, as they are not precise.
17. Explain why the motion of a bicycle is considered both rotational and rectilinear motion.
Answer:
The
wheels rotate
around their axis – showing
rotational motion
.
The bicycle
moves forward in a straight line
– showing
rectilinear motion
.
The pedals also
rotate in a circular motion
.
If the bicycle takes a curved turn, it shows
circular motion
.
This combination of motion types is common in
vehicles and machines
.
Many objects in real life exhibit
multiple types of motion simultaneously
.
18. How does the motion of a simple pendulum work?
Answer:
A pendulum consists of a
string and a bob
.
When displaced, it moves back and forth in a
fixed path
.
This type of motion is called
periodic motion
.
The time taken for one complete swing is called
time period
.
Factors like
length of the string
affect the time period.
Examples:
Wall clocks, grandfather clocks, metronomes
use pendulum motion.
19. What is the importance of motion in machines and vehicles?
Answer:
Machines work based on motion
(e.g., gears in a clock).
Vehicles move using different types of motion
(rectilinear + rotational).
Machines convert energy into motion
, making tasks easier.
Motion enables industries to function
, producing goods and services.
Everyday transportation
depends on motion (cars, trains, airplanes).
Robotics and automation use motion
for precise operations.
20. What is the role of measurement in science and daily life?
Answer:
Science experiments
require precise measurement (e.g., chemistry, physics).
Building construction
depends on accurate measurements.
Cooking recipes need proper quantity measurements
for taste.
Health sector:
Doctors measure weight, height, and body temperature.
Sports:
Races and games depend on time and distance measurements.
Trade and business require measurement
(e.g., selling cloth, land, fuel).
