• Science is the systematic study of nature
and how it affects us and our environment.
• Science can explain natural phenomena
that happen in our environment.
– Through careful observations, studies and
VARIOUS FIELDS IN SCIENCE
• Science covers a very wide area of study and is
divided into various fields, such as:
– Biology: the study of living things
– Physics : the study of interaction of matter and energy
– Chemistry : the study of composition and chemical
properties of substances, their reactions and uses
– Geology : the study of rocks and minerals
– Astronomy : the study of the stars and planets
– Meteorology : the study of weather and climate
Forming a hypothesis
Planning the experiment
Controlling the variables
Analysing and interpreting data
Drawing a conclusion
Writing a report
1. List the steps of scientific
2. Write down a report on Simple
• To investigate how the length of the pendulum
string affect the time for 10 complete swings
of the pendulum.
• How the length of the pendulum string affect
the time for 10 complete swings of the
• If the length of the pendulum is longer, the
time taken for 10 complete swing of the
pendulum is longer.
• Manipulated (what to change)
: the length of the pendulum
• Responding (what is observed)
: time taken for 10 complete swings
• Constant (kept the same)
: mass of the pendulum bob
• Pendulum bob, string/thread, retort stand and
clamp, stop watch
• Apparatus set-up:
1. Prepare the simple pendulum with a 10cm long
2. Pull the pendulum bob to one side, then release.
3. Record the time taken for 10 complete
oscillations in a table.
4. Repeat the experiment using a simple pendulum
of different lengths, e.g. 20cm, 30cm, 40cm and
5. Draw a graph showing the time taken versus
length of pendulum for 10 complete oscillations.
1. A simple pendulum with a 10 cm long thread was
2. The pendulum was pulled to one side, and then
3. The time taken for 10 complete oscillations was
recorded in a table.
4. The experiment was repeated using a simple
pendulum with 20cm, 30cm, 40 and 50cm long.
5. A graph showing the time taken versus length of
pendulum for 10 complete oscillations was drawn.
• Graph of time taken for 10 complete oscillations
versus length of simple pendulum.
From the graph, we can say that:
1. The pendulum with a longer string takes
longer time to oscillate than the
pendulum with a shorter string.
2. The time taken for the pendulum to make one
complete oscillation will increase when the
pendulum string is longer.
• From the results, the hypothesis is
• The time taken for the simple pendulum to
make one complete oscillation increases
with the length of the pendulum.
• Measurement is important because:
–It helps to describe things everyday;
–It is a part of the scientific investigation
(e.g: simple pendulum experiment)
Can be measured
Cannot be measured
How far is your house to How beautiful a person
How long does you take
How does a durian
to finish your
How hot is a glass of
How soft a pillow is?
How a flower smell?
• A physical quantity is something that can be
• There are five basic quantities: length, time,
mass, temperature and electric current.
• Measurement of physical quantities consist of
– A number indicating value or how much;
– A unit of measurement.
• Unit is a scale that helps you understand
a particular measurement.
• S.I units: International standard unit of
measurement (Systeme International d’
Allow us to analyse data and compare
information easily and more accurately;
No confusion because there is specific
symbols for each unit;
Allow us to solve problems related to
A measurement of how long
something from one point to another
A measurement of how much matter
there is in an object
A measurement of the interval
between two events
A measurement of the warmness or
coldness in any object
A measurement of the rate flow of
electric charges through a circuit
• Prefixes are added to units like meter and
gram when we need to state values that are
too small or too large.
• The weight of an object is the pull of the Earth
(force of gravity) on the object.
• The S.I unit of weight is Newton (N).
• The weight of any object depends on the
• The weight of an object is obtained using a
spring balance or compression spring
• The mass of an object is the quantity of
matter in the object.
• The S.I. unit of mass is kilogram (kg).
• The mass of an object can be obtained using a
triple beam balance or lever balance.
It is the amount of
matter in an object.
Its value is fixed.
Unit: kilogram (kg)
It is the gravitational
pull on an object.
Its value varies from
place to place.
Unit: Newton (N)
Measured using beam Measured using spring
balance or lever
balance or weighing
1. Tools: ruler, metre rule, measuring tape
2. Measuring the length of a straight line:
– Using metre rule or a ruler
– Correct position of eye (to avoid parallax error)
3. Measuring the length of a curve:
a) Using a ruler and a piece of thread
A knot is tied at the end of a thread
The thread is stretched along the curve carefully
Make a mark at the end of the curve
Stretch the thread along the ruler to obtain the length
b) Using an opisometer
• Measuring the diameter of a spherical
– Using two wooden blocks and a ruler
– Using a set-square and a ruler
• Measuring the diameter of an object:
– The external diameter is measured using external
calipers and a ruler
– The internal diameter is measured using internal
caliper and a ruler.
• Measuring the thickness of an object:
– The thickness of a piece of paper can be
determined by measuring the thickness of a stack
of papers and dividing the value of number of
sheets of paper.
of a single sheet
of a stack of paper
Number of sheets
– The thickness of a glass tube can be measured by
taking the difference between its external and
• Area is the total surface covered by an object.
• The SI unit is square metre (m2).
• Regular-shaped areas can be calculated using
Mathematical formula. (next slide)
Irregular-shaped areas can be estimated by using a graph paper.
– Trace the object on the
– Estimate the area by
counting the number of full
squares, half full squares
and more than half full
squares (tick the squares)
– Area of the object is
estimated by multiplying the
number of squares with the
area of one square.
– The area can be estimated
more accurately with
• Volume of an object is the total space
occupied by the object.
• The SI unit is cubic metre (m3).
• It also can be measured in millilitre (ml).
• The apparatus: measuring cylinder, burette
1 ml = 1 cm3
1 l = 1000 cm3= 1000 ml
1 m3= 1 000 000 cm3 = 1 000 000 ml
• Measuring volumes of liquids
– The volume must be taken at the meniscus level
of the liquid.
– Use a piece of white paper to enable the
meniscus to be seen clearly.
– The eye is positioned at the same level of the
meniscus to avoid parallax error.
• Measuring volumes of solids
– The volume of regular-shaped and irregular-shaped
can be measured using water displacement method.
– The object to be measured must be submerged in the
measuring cylinder filled with water.
– The volume of the water displaced is the volume of
– The volume of a solid can also be measured using
a displacement can or a Eureka can.
– The volume of the water that flows out from the
can is the volume of the solid measured.
– The volume of a light object can be measured
with the aid of a weight, for example, a stone.
– The stone which is tied to the cork enables the
cork to be submerged in the water.
1. Temperature is the degree of of hotness or
coldness of a substance.
2. The S.I unit for temperature is Kelvin (K).
Normally temperature is measured in degree
3. The temperature of a liquid is measured by using
a laboratory thermometer.
4. Pure water boils at 100°C and freezes at 0°C under
5. The average body temperature is 36.9°C.
6. The temperature of our body is measured by
using a clinical thermometer.
1. In the past, different units were used by
different people for measuring for measuring
the same basic quantity.
2. Using different units gives rise to several
problem such as;
a) It is difficult to make comparisons
b) Foreign tourists may not understand the units
used in the countries they visit.
• Inch, foot, yard, cubit, mile
• Centimetre, metre, kilometre.
1 inch = 2.54 cm
1 foot = 12 inches = 0.3048 m
1 yard = 0.9144 m
1 mile = 1609 m
• Ounce, pound
• Tahil, kati
• Gram, kilogram
1 ounce = 28.35 g
1 pound = 0.4536 kg
1 kati = 16 tahils
3. The use of standard units in measurements is
very important to scientist and people who
import and export goods.
4. Using standard units enable scientists;
a) To understand one another’s measurement and
make accurate comparisons,
b) To communicate and understand one another’s
experiment and research,
c) To exchange information, knowledge and
d) To avoid confusion.