# Junior 1 Science Introduction To Science

Topics: Kilogram, Mass, International System of Units Pages: 46 (580 words) Published: March 8, 2015
Junior 1 Science
1)Introduction to Science
2)Cell As A Unit of Life
3)Matter
4)The Variety of Resources on Earth
5)The Air Around Us
6)Sources of Energy
7)Heat

Science is part of everyday
life
What is Science?

Science is
the study of
natural
phenomena
,

Natural phenomena are incidents
that take place on their own in our
natural surroundings

Examples of Natural
Phenomena

Technology
Application

of scientific
knowledge for the needs of
mankind

Uses & Benefits of Science
Help us to solve problems
 To make things quickly
 To make our work easier
 To enjoy our leisure
 Makes communication easy
 To maintain good health

Science Laboratory Apparatus &
Their Uses

HAZARD SYMBOLS!!!!

Steps in Scientific Investigation
Identifying the problem

Suggesting a hypothesis
Constant

Identifying the variables

Manipulated
Responding

Carry out
experiment
Collecting
data/observations
Analysing and
interpreting data

Forming a conclusion

Result
support
hypothesis

Scientific
theory is
formed

Result do
not support
hypothesis

Hypothesis
is rejected

Physical Quantities and their units
• 5 physical quantities

SI units and symbols
Physical
quantities

SI Units

Symbol

Length
Mass
Time
Temperature
Electrical
Current

Metre
Kilogram
Second
Kelvin
Ampere

m
kg
s
K
A

Prefixes and Symbols for Units

Kilogram (kg)

Gram (g)

Miligram (mg)

0.4

400

400000

2.5

2500

250000

0.0062

6.2

6200

5000
45
750

Kilometre
(km)

metre (m)

desimetre dm) Centimetre(cm)

400
2.5
850
5000
45
750

The uses of measuring tools
MEASURING LENGTH

Vernier callipers

Micrometer

Measuring area
Units for length

Unit for area

mm

mm²

cm

cm²

m

km

km²

To measure the regular area

To estimate area of irregular figure

Measuring the volume of liquid

• 1cm³ = 1ml
• 1l = 1000ml

Measuring the Volume of an Irregular Solid
• Can be determined by using water

displacement method

Measuring the volume of a cork

Measuring the volume of a solid using an
eureka can

Measuring the temperature of a liquid
Measured by a
thermometer in degree
celcius

Measuring the body temperature

CONCEPT OF MASS
Weight
The weight of an object is the pull
of force of gravity of the Earth
on it.
Can

be measured using:
 Newton spring balance
 Compression spring balance

• The weight of an object varies from place to place
because the Earth’s gravitational pull is different
in different places
• The weight of an object decrease as it moves
away from the Earth
• The moon’s gravitational pull is only 1/6 of the
Earth’s

NEWTON SPRING
BALANCE

COMPRESSION SPRING
BALANCE

Mass
Quantity

of matter in the object
Cannot change  because it
always contains the same
amount of substance
Measured by using:
Lever balance
Triple beam balance
Butchart lever balance

• 1kg = 1000g
• 1g = 1000mg
• 1tonne = 1000kg

Triple beam balance

Butchart
balance
Lever balance

Electronic Balance

Differences between mass and weight
MASS
Quantity of matter
contained in an
object
Kilogram
Lever balance, triple
beam balance,
Butchart balance,
electronic balance
Mass of an object
does not change

DIFFERENCES
Definition
SI Unit
Measuring
tools
Characteristics

WEIGHT
The Earth’s
gravitational pull on
an object
Newton (N)
Newton spring
balance,
compression spring
balance
Weight of an object
changes from place
to place

Im portance of SI U nits in
m easurem ent
Using different units gives rise to
several problem:
 It is difficult to make
comparisons
 Foreign tourists may not
understand the units used in the
countries they visit

Some other units used
• Inches, feet, yard, mile
• Pound

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