Physical quantities and measurement techniques
Definition:
Physical quantities are things that can be measured and written using numbers and units.
Examples of Physical Quantities:
Length – how long something is
Mass – how heavy something is
Time – how long an activity takes
Temperature – how hot or cold something is
Volume – how much space something occupies
Units of Measurement:
Each physical quantity has a unit.
Physical Quantity Unit Length metre (m), centimetre (cm)Mass kilogram (kg), gram (g)Time second (s), minute (min)Temperature degree Celsius (°C)Volume litre (L), millilitre (mL)
Measurement Techniques :
1. Measuring Length
Tools: ruler, metre scale, measuring tape
Example: Length of a pencil
2. Measuring Mass
Tools: balance, weighing scale
Example: Weight of a book
3. Measuring Time
Tools: clock, watch, stopwatch
Example: Time taken to run a race
4. Measuring Temperature
Tool: thermometer
Example: Body temperature
5. Measuring Volume
Tools: measuring jar, measuring cup
Example: Amount of water in a bottle
Important Points:
Always use the correct unit while measuring.
Measuring helps us compare objects correctly.
Standard units give accurate results.
Fun Fact
Without measurement, we cannot know how big, heavy, fast, or hot something is!