4. 1.6 Discussion Activity Physical quantity SI Unit Symbol Length metre
Mass
Kilogram Kg
Temperature
Kelvin K
Electrical current
Ampere A
Time
second s

5. MASS
The mass of an object is the quantity of matter contained in the object.
The SI unit for mass is kilogram (kg).

6. WEIGHT The earth pulls objects to its centre.
This pull is called the force of gravity or gravitational force.
The weight of an object is the pull of the Earth on the object
The SI unit for weight is Newton (N).

7. Which one is heavier?

8. WEIGHT AND MASS WEIGHT MASS Quantity of matter contained in an object.
DIFFERENCES
Quantity of matter contained in an object.
The pull of the Earth’s gravity on that object.
Kilogram (kg)
Newton (N)
Lever balance
Triple beam balance
Newton spring balance
Compression balance
Mass of an object does
not change
Weight of an object changes from place to place
Not effect by gravity
Effect by gravity
DEFINITION
SI UNIT
MEASURING
TOOLS
CHARACTERISTIC
PROPERTY
Also measured in grams(g) and
miligrams(mg) kg=1 000 g
1 g=1 000 mg

9. WEIGHT AND MASS
Relationship between weight and mass: N = 100 g 10 N = g = 1 kg
Why weight of an object changes from place to place?
The Earth’s gravitational pulls different in different places.
- Weight of an object is heavier at the North Pole and South
Pole than at the equator.
The moon gravitational pull is only 1/6 of the Earth’s.
- Example:
An astronaut weighing 600 N on the Earth will weigh only 100 N on the moon.

10. MEASURING TOOLS Measurement of length
Measurement of the diameter of an object
Measurement of area
Measurement of volume of liquid
Measurement of volume of solids

11. Topic : Measurement of length What is length?
Length is the distance between two points.
The SI unit for length is metre(m),but the units kilometre(km), centimetre(cm) and milimetre(mm) are also used.
How length can be measured?
1 cm = 10mm
1 m = 100 cm
1 km = 1000 m
Length
Measuring tools
1) Straight line
Metre ruler
Measuring tape
2) Curved line
Thread and ruler
Opisometer
NOTE: To get accurate or precise reading, three(3) measurements are usually taken

12. Measurement of diameter
Topic :
Measurement of diameter
What is diameter?
A straight line drawn from side to side through the centre of circle.
How diameter can be measured?
diameter
2 types
Internal diameter
External diameter
Diameter Measuring tools
Internal diameter Internal calipers and ruler
External diameter External calipers and ruler

13. Topic : Measurement of Area √ X What is area?
Area is the total surface or space occupied by an object
The units for area are square metres (m²)
square centimetres (cm²)
square milimetres (mm²)
Types of area
Area of regular shapes
Area of irregular shapes
Area of
How to calculate
1)Square/
rectangle
Area = length x width
2) Triagle
Area =(½ )x base x height
Estimated by using graph paper
Examples: leaves & petals √ X

14. Topic : Measurement of Area √ X What is area?
Area is the total surface or space occupied by an object
The units for area are square metres (m²)
square centimetres (cm²)
square milimetres (mm²)
Types of area
Area of regular shapes
Area of irregular shapes
Area of
How to calculate
1)Square/
rectangle
Area = length x width
2) Triangle
Area =(½ )x base x height
Estimated by using graph paper
Examples: leaves & petals √ X

15. Topic : Measurement of Volume What is volume?
Volume is the total space occupied by an object
The units for volume are cubic metres (m³)
cubic centimetres (cm³)
cubic milimetres (mm³)
liters (∫) and mililitres(m∫)
1 m∫ = 1 cm³
1 ∫ = m∫
= cm³
Types of volume
Volume of liquids
Volume of solids
2 types of solids
Regular-shaped
Irregular-shaped
Measured by:
Measuring cylinder
Pipette
Burette
Determined by using
water displacement method

16. Topic : Measurement of Volume What is volume?
Volume is the total space occupied by an object
The units for volume are cubic metres (m³)
cubic centimetres (cm³)
cubic milimetres (mm³)
liters (∫) and mililitres(m∫)
1 m∫ = 1 cm³
1 ∫ = m∫
= cm³
Types of volume
Volume of liquids
Volume of solids
2 types of solids
Regular-shaped
Irregular-shaped
Measured by:
Measuring cylinder
Pipette
Burette
Determined by using
water displacement method

17. End of chapter 1
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