Science Form 1 (Chapter 1)

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Chapter 1 Introduction to Science
Science Form 1
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WHAT IS SCIENCE?

• 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.
• How?
• Through careful observations, studies and
  scientific investigations.

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List some of natural phenomena
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CAREERS IN SCIENCE
Environmentalist
Archeologist
Doctor
Forensic technician
Science teacher
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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

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A SCIENCE LABORATORY
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What are the good practices demonstrated by the
student?

• Wearing goggles
• Carrying bottles by the body not the neck

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GENERAL RULES AND SAFETY PRECAUTIONS
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COMMON LABORATORY APPARATUS
Bunsen burner
Tripod stand and wire gauze
Test tube
Crucible
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Syringe
Test tube holder
Retort stand and clamp
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• 1.2 Scientific Investigation

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Steps in scientific investigation

1. Identifying problem
2. Forming a hypothesis
3. Planning the experiment
4. Controlling the variables
5. Collecting data
6. Analysing and interpreting data
7. Drawing a conclusion
8. Writing a report

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• List the steps of scientific
• investigation.

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• 2. Write down a report on Simple
• pendulum experiment.

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Simple pendulum experiment
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WRITING A REPORT

• Aim
• Problem statement
• Hypothesis
• Variables
• Materials and apparatus
• Procedure
• Results
• Analysis
• Conclusion

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1. Aim

• To investigate how the length of the pendulum
  string affect the time for 10 complete swings of
  the pendulum.

2. Problem statement

• How the length of the pendulum string affect the
  time for 10 complete swings of the pendulum?

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3. Hypothesis

• If the length of the pendulum is longer, the time
  taken for 10 complete swing of the pendulum is
  longer.

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4. Variables

• 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

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5. Materials and apparatus

• Pendulum bob, string/thread, retort stand and
  clamp, stop watch
• Apparatus set-up

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6. Procedure (active sentence)

1. Prepare the simple pendulum with a 10cm long
   thread.
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
   50cm.
5. Draw a graph showing the time taken versus length
   of pendulum for 10 complete oscillations.

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6. Procedure (change to passive sentence when
writing a report)

1. A simple pendulum with a 10 cm long thread was
   prepared.
2. The pendulum was pulled to one side, and then was
   released.
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.

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7. Results (data table)
Experiment Length of simple pendulum ( cm ) Time taken for 10 complete oscillations ( s )
1 10 10
2 20 13
3 30 15
4 40 18
5 50 20
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7. Results (data table)
Experiment Length of simple pendulum ( cm ) Time taken for 10 complete oscillations ( s ) Time taken for 1 complete oscillations ( s )
1 10 10 1.0
2 20 13 1.3
3 30 15 1.5
4 40 18 1.8
5 50 20 2.0
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8. Analysis

• Graph of time taken for 10 complete oscillations
  versus length of simple pendulum.

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8. Analysis

• From the graph, we can say that
• The pendulum with a longer string takes
• time to oscillate than the pendulum with a
  shorter string.
• 2. The time taken for the pendulum to make one
• complete oscillation will
  when the
• pendulum string is longer.

longer
increase
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9. Conclusion

• From the results, the hypothesis is
  .
• The time taken for the simple pendulum to make
  one complete oscillation
  with the length of the pendulum.

accepted
increases
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1.3 physical quantities and their units
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measurement

• Measurement is important because
• It helps to describe things everyday
• It is a part of the scientific investigation
  process
• (e.g simple pendulum experiment)

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Measurement
Can be measured Cannot be measured
How far is your house to the school? How beautiful a person is?
How long does you take to finish your homework? How does a durian taste?
How hot is a glass of water? How soft a pillow is?
How a flower smell?
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Physical quantities

• A physical quantity is something that can be
  measured.
• There are five basic quantities length, time,
  mass, temperature and electric current.
• Measurement of physical quantities consist of two
  parts
• A number indicating value or how much
• A unit of measurement.

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Standard units S.I. Units

• Unit is a scale that helps you understand a
  particular measurement.
• S.I units International standard unit of
  measurement (Systeme International d Unites).

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Importance of standard units

• 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
  measurement.

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Five basic quantities
Physical quantities SI units Symbols Definition
Length Metre m A measurement of how long something from one point to another
Mass Kilogram kg A measurement of how much matter there is in an object
Time Second s A measurement of the interval between two events
Temperature Kelvin K A measurement of the warmness or coldness in any object
Electric current Ampere A A measurement of the rate flow of electric charges through a circuit
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Prefixes

• Prefixes are added to units like meter and gram
  when we need to state values that are too small
  or too large.

Prefix Multiplier Symbol Numerical value
Micro X 10-6 µ 0.000001
Milli X 10-3 m 0.001
Centi X 10-2 c 0.01
Kilo X 103 k 1000
Mega X 106 M 1000000
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1.4 CONCEPT OF MASS AND WEIGHT
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WHAT IS WEIGHT?

• 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
  gravitational force.
• The weight of an object is obtained using a
  spring balance or compression spring balance.

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WHAT IS MASS?

• 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.

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Exercise 5 Can u differentiate between mass and
weight?
MASS WEIGHT




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Can u differentiate between mass and weight?
MASS WEIGHT
It is the amount of matter in an object. It is the gravitational pull on an object.
Its value is fixed. Its value varies from place to place.
Unit kilogram (kg) Unit Newton (N)
Measured using beam balance or lever balance. Measured using spring balance or weighing balance.
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1.6) MEASURING TOOLS
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Measuring Length

• Tools ruler, metre rule, measuring tape
• Measuring the length of a straight line
• Using metre rule or a ruler
• Correct position of eye (to avoid parallax error)

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• Measuring the length of a curve
• 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
• Using an opisometer

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• Measuring the diameter of a spherical object
• Using two wooden blocks and a ruler
• Using a set-square and a ruler

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• 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.

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• 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.

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• The thickness of a glass tube can be measured by
  taking the difference between its external and
  internal diameter.

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Measuring Area

• 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)

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Irregular-shaped areas can be estimated by using
a graph paper.

• Trace the object on the graph paper.
• 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
  smaller squares.

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Measuring volume

• 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 and
  pipette.

1 ml 1 cm3 1 l 1000 cm3 1000 ml 1 m3 1 000
000 cm3 1 000 000 ml
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• 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.

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• 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 object.

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• 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.

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• 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.

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Measuring temperature

• Temperature is the degree of of hotness or
  coldness of a substance.
• The S.I unit for temperature is Kelvin (K).
  Normally temperature is measured in degree
  Celsius (C).
• The temperature of a liquid is measured by using
  a laboratory thermometer.
• Pure water boils at 100C and freezes at 0C
  under normal condition.
• The average body temperature is 36.9C.
• The temperature of our body is measured by using
  a clinical thermometer.

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Clinical Thermometer
Laboratory Thermometer
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1.7) The importance of standard units

• In the past, different units were used by
  different people for measuring for measuring the
  same basic quantity.
• Using different units gives rise to several
  problem such as
• It is difficult to make comparisons
• Foreign tourists may not understand the units
  used in the countries they visit.

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Basic quantity Unit used
Length 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
Mass Ounce, pound Tahil, kati Gram, kilogram 1 ounce 28.35 g 1 pound 0.4536 kg 1 kati 16 tahils
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• The use of standard units in measurements is very
  important to scientist and people who import and
  export goods.
• Using standard units enable scientists
• To understand one anothers measurement and make
  accurate comparisons,
• To communicate and understand one anothers
  experiment and research,
• To exchange information, knowledge and technology
• To avoid confusion.

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