Introduction to Physical Introduction to Physical ScienceScience

Chapter 1Chapter 1Modified from Holt, Rinehart, and Winston presentation for textbook Modified from Holt, Rinehart, and Winston presentation for textbook

Science Spectrum: Physical ScienceScience Spectrum: Physical Science

Section 1 The Nature of Science

ObjectivesObjectives

Describe Describe the main branches of natural science and the main branches of natural science and relate them to each other.relate them to each other.

Describe Describe the relationship between science and the relationship between science and technology.technology.

Distinguish Distinguish between scientific laws and scientific between scientific laws and scientific theories.theories.

Explain Explain the roles of models and mathematics in the roles of models and mathematics in scientific theories and laws.scientific theories and laws.

Chapter 1

How Does Science Take Place?How Does Science Take Place? Scientists investigate.Scientists investigate.

Scientists plan experiments.Scientists plan experiments.

Scientists observe.Scientists observe.

Scientists always test the results.Scientists always test the results.

Section 1 The Nature of ScienceChapter 1

How Does Science Take Place? How Does Science Take Place? continuedcontinued

Science has many branches.Science has many branches.

• Biological scienceBiological science is the science of living things.is the science of living things.• Physical sciencePhysical science is the science of matter and energy.is the science of matter and energy.• Earth science is the science of the Earth, the atmosphere, Earth science is the science of the Earth, the atmosphere,

and weather.and weather.

ScienceScience. is the knowledge obtained by observing . is the knowledge obtained by observing natural events and conditions in order to discover natural events and conditions in order to discover facts and formulate laws or principles that can be facts and formulate laws or principles that can be verified or tested.verified or tested.

Section 1 The Nature of ScienceChapter 1

Natural ScienceNatural Science

Section 1 The Nature of ScienceChapter 1

How Does Science Take Place? How Does Science Take Place? Science and technology work together.Science and technology work together.

• Some scientists practice pure science defined as Some scientists practice pure science defined as the continuing search for scientific knowledge.the continuing search for scientific knowledge.

• Some scientists and engineers practice applied Some scientists and engineers practice applied science defined as the search for ways to use science defined as the search for ways to use scientific knowledge for practical applications.scientific knowledge for practical applications.

Technology Technology is the application of science for is the application of science for practical purposes.practical purposes.

Section 1 The Nature of ScienceChapter 1

Scientific Laws and TheoriesScientific Laws and Theories Laws and theories are supported by Laws and theories are supported by

experimental results.experimental results.

Scientific theories are always being questioned Scientific theories are always being questioned and examined. To be valid, a theory must:and examined. To be valid, a theory must:

• explain observationsexplain observations• be repeatablebe repeatable• be predictablebe predictable

Section 1 The Nature of ScienceChapter 1

Scientific Laws and Theories, Scientific Laws and Theories, continuedcontinued

Scientific FactsScientific Facts change (i.e. World is flat) change (i.e. World is flat)

Scientific law Scientific law a summary of many a summary of many experimental results and observations; a law experimental results and observations; a law tells how things worktells how things work

Scientific theory Scientific theory an explanation for some an explanation for some phenomenon that is based on observation, phenomenon that is based on observation, experimentation, and reasoningexperimentation, and reasoning

Section 1 The Nature of ScienceChapter 1

Scientific Laws and TheoriesScientific Laws and Theories Mathematics can describe physical events.Mathematics can describe physical events.

• A qualitative statement describes something with A qualitative statement describes something with words.words.

• A quantitative statement describes something with A quantitative statement describes something with mathematical equations.mathematical equations.

Section 1 The Nature of ScienceChapter 1

Scientific Laws and TheoriesScientific Laws and Theories

Models can represent physical events.Models can represent physical events.

• A model is a representation of an object or event A model is a representation of an object or event that can be studied to understand the real object or that can be studied to understand the real object or event.event.

• Scientists use physical and computer models to Scientists use physical and computer models to study objects and events.study objects and events.

Section 1 The Nature of ScienceChapter 1

ModelsModels

Section 1 The Nature of ScienceChapter 1

Physical, Mathematical, and Physical, Mathematical, and Conceptual ModelsConceptual Models

Section 1 The Nature of ScienceChapter 1

Section 2 The Way Science Works

ObjectivesObjectives

Understand Understand how to use critical thinking skills to how to use critical thinking skills to solve problems.solve problems.

Describe Describe the steps of the scientific method.the steps of the scientific method. Know Know some of the tools scientists use to investigate some of the tools scientists use to investigate

nature.nature. Explain Explain the objective of a consistent system of units, the objective of a consistent system of units,

and identify the SI units for length, mass, and time.and identify the SI units for length, mass, and time. Identify Identify what each common SI prefix represents, and what each common SI prefix represents, and

convert measurements.convert measurements.

Chapter 1

Science SkillsScience Skills

Critical thinking Critical thinking is the ability and willingness is the ability and willingness to assess claims critically and to make to assess claims critically and to make judgments on the basis of objective and judgments on the basis of objective and supported reasons. supported reasons. Scientists approach a problem by thinking Scientists approach a problem by thinking

logically. logically.

Section 2 The Way Science WorksChapter 1

Science Skills, Science Skills, continuedcontinued Using the scientific methodUsing the scientific method

Scientific method Scientific method a series of steps followed to a series of steps followed to solve problems including collecting data, solve problems including collecting data, formulating a hypothesis, testing the formulating a hypothesis, testing the hypothesis, and stating conclusionshypothesis, and stating conclusions

Section 2 The Way Science WorksChapter 1

Scientific MethodScientific Method

Section 2 The Way Science WorksChapter 1

Science Skills, Science Skills, continuedcontinued Testing hypothesesTesting hypotheses

• Scientists test a hypothesis by doing a controlled Scientists test a hypothesis by doing a controlled experiment.experiment.

• In a controlled experiment, all the factors that could affect In a controlled experiment, all the factors that could affect the experiment are kept constant except for one change.the experiment are kept constant except for one change.

Hypothesis Hypothesis a possible explanation or answer that can a possible explanation or answer that can be testedbe tested

Variable Variable a factor that changes in an experiment in a factor that changes in an experiment in order to test a hypothesisorder to test a hypothesis

Section 2 The Way Science WorksChapter 1

Controlled Experiment and Controlled Experiment and VariableVariable

Section 2 The Way Science WorksChapter 1

Science Skills, Science Skills, continuedcontinued Conducting experimentsConducting experiments

• No experiment is a failureNo experiment is a failure

• The results of every experiment can be used to The results of every experiment can be used to revise the hypothesis or plan tests of a different revise the hypothesis or plan tests of a different variable.variable.

Section 2 The Way Science WorksChapter 1

Science Skills, Science Skills, continuedcontinued Using scientific toolsUsing scientific tools

• There are many tools used by scientists for making There are many tools used by scientists for making observations, includingobservations, including

• microscopesmicroscopes• telescopestelescopes• spectroscopesspectroscopes• particle acceleratorsparticle accelerators• computerscomputers

Section 2 The Way Science WorksChapter 1

Units of MeasurementUnits of Measurement SI units are used for consistency.SI units are used for consistency.

• Scientists use the International System of Units (SI) to Scientists use the International System of Units (SI) to make sharing data and results easier. make sharing data and results easier.

Section 2 The Way Science WorksChapter 1

SI (Le Système Internationale SI (Le Système Internationale d’Unités)d’Unités)

Section 2 The Way Science WorksChapter 1

Units of Measurement, Units of Measurement, continuedcontinuedSI prefixes are for very large and very small SI prefixes are for very large and very small

measurements.measurements. The table below shows SI prefixes for large The table below shows SI prefixes for large

measurements.measurements.

Section 2 The Way Science WorksChapter 1

Units of Measurement, Units of Measurement, continuedcontinued The table below shows SI prefixes for small The table below shows SI prefixes for small

measurements.measurements.

Section 2 The Way Science WorksChapter 1

Math SkillsMath SkillsConversions Conversions A roll of copper wire contains 15 A roll of copper wire contains 15

m of wire. What is the length of the wire in m of wire. What is the length of the wire in centimeters?centimeters?

1. List the given and unknown values.1. List the given and unknown values.Given: Given: length in meters, llength in meters, l = 15 m = 15 m

Unknown: Unknown: length in centimeters = ? length in centimeters = ? cmcm

Section 2 The Way Science WorksChapter 1

Math SkillsMath Skills2. Determine the relationship between units.2. Determine the relationship between units.

This also means that 1 m = 100 cm.This also means that 1 m = 100 cm.

3. Write the equation for the conversion.3. Write the equation for the conversion.

100 cm

1 m

Section 2 The Way Science WorksChapter 1

Math SkillsMath Skills

length in cm = 1500 cm

4. Insert the known values into the equation, 4. Insert the known values into the equation, and solve.and solve.

Section 2 The Way Science WorksChapter 1

Units of Measurement, Units of Measurement, continuedcontinued Making measurementsMaking measurements

• Many observations rely on quantitative measurements.Many observations rely on quantitative measurements.

Length Length a measure of the straight-line distance a measure of the straight-line distance between two pointsbetween two points

Mass Mass a measure of the amount of matter in an objecta measure of the amount of matter in an object Volume Volume a measure of the size of a body or region in a measure of the size of a body or region in

three-dimensional spacethree-dimensional space Weight Weight a measure of the gravitational force exerted a measure of the gravitational force exerted

on an objecton an object

Section 2 The Way Science WorksChapter 1

Section 3 Organizing Data

ObjectivesObjectives

Interpret Interpret line graphs, bar graphs, and pie charts.line graphs, bar graphs, and pie charts.

Use Use scientific notation and significant figures in scientific notation and significant figures in problem solving.problem solving.

Identify Identify the significant figures in calculations.the significant figures in calculations.

Understand Understand the difference between precision the difference between precision and accuracy.and accuracy.

Chapter 1

Presenting Scientific DataPresenting Scientific Data Line graphs are best for continuous change.Line graphs are best for continuous change.

• Line graphs are usually made with the x-axis showing the Line graphs are usually made with the x-axis showing the independent variable and the y-axis showing the dependent independent variable and the y-axis showing the dependent variable. variable.

• The values of the dependent variable depend on what The values of the dependent variable depend on what happens in the experiment. happens in the experiment. What you measure!What you measure!

• The values of the independent variable are set before the The values of the independent variable are set before the experiment takes place. experiment takes place. What you control!What you control!

Section 3 Organizing DataChapter 1

Line GraphLine Graph

Section 3 Organizing DataChapter 1

Presenting Scientific Data, Presenting Scientific Data, continuedcontinued

Bar graphs compare items.Bar graphs compare items.

• A bar graph is useful for comparing similar data A bar graph is useful for comparing similar data for several individual items or events.for several individual items or events.

• A bar graph can make clearer how large or small A bar graph can make clearer how large or small the differences in individual values are.the differences in individual values are.

Section 3 Organizing DataChapter 1

Bar GraphBar Graph

Section 3 Organizing DataChapter 1

Presenting Scientific Data, Presenting Scientific Data, continuedcontinued

Pie charts show parts Pie charts show parts of a whole.of a whole.• A pie chart is ideal for A pie chart is ideal for

displaying data that displaying data that are parts of a whole.are parts of a whole.

• Data in a pie chart is Data in a pie chart is presented as a presented as a percent.percent.

Section 3 Organizing DataChapter 1

Writing Numbers in Scientific Writing Numbers in Scientific NotationNotation

Scientific notation Scientific notation is a method of expressing is a method of expressing a quantity as a number multiplied by 10 to the a quantity as a number multiplied by 10 to the appropriate power.appropriate power.

Some powers of 10 and their decimal Some powers of 10 and their decimal equivalents are shown below.equivalents are shown below.

• 101033 = 1000 = 1000• 101022 = 100 = 100• 101011 = 10 = 10• 101000 = 1 = 1• 1010-1-1 = 0.1 = 0.1• 1010-2-2 = 0.01 = 0.01• 1010-3-3 = 0.001 = 0.001

Section 3 Organizing DataChapter 1

Writing Numbers in Scientific Writing Numbers in Scientific Notation, Notation, continuedcontinued

Using scientific notationUsing scientific notation

• RulesRules• First # will be between 1-10.First # will be between 1-10.• Exponents is determined by how far we move the decimal. Exponents is determined by how far we move the decimal.

• When you use scientific notation in calculations, you When you use scientific notation in calculations, you follow the math rules for powers of 10.follow the math rules for powers of 10.

• When you multiply two values in scientific notation, you When you multiply two values in scientific notation, you add the powers of 10. When you divide, you subtract the add the powers of 10. When you divide, you subtract the powers of 10.powers of 10.

Section 3 Organizing DataChapter 1

Math SkillsMath SkillsWriting Scientific Notation Writing Scientific Notation The adult human The adult human

heart pumps about 18 000 L of blood each heart pumps about 18 000 L of blood each day. Write this value in scientific notation.day. Write this value in scientific notation.

1. List the given and unknown values.1. List the given and unknown values.

Section 3 Organizing DataChapter 1

Scientific NotationScientific Notation

Section 3 Organizing DataChapter 1

Math SkillsMath SkillsUsing Scientific Notation Using Scientific Notation Your state plans to Your state plans to

buy a rectangular tract of land measuring 5.36 buy a rectangular tract of land measuring 5.36 x 10x 1033 m by 1.38 x 10 m by 1.38 x 1044 m to establish a nature m to establish a nature preserve. What is the area of this tract in preserve. What is the area of this tract in square meters?square meters?

Section 3 Organizing DataChapter 1

Using Significant FiguresUsing Significant FiguresPrecision and accuracyPrecision and accuracy

Precision Precision the exactness of a measurementthe exactness of a measurement

Accuracy Accuracy a description of how close a a description of how close a measurement is to the true value of the measurement is to the true value of the quantity measuredquantity measured

Section 3 Organizing DataChapter 1

Accuracy and Precision, part 1Accuracy and Precision, part 1

Section 3 Organizing DataChapter 1

Accuracy and Precision, part 2Accuracy and Precision, part 2

Section 3 Organizing DataChapter 1

Section 3 Organizing DataChapter 1

Using Significant Figures, Using Significant Figures,

Significant figure Significant figure a prescribed decimal place a prescribed decimal place that determines the amount of rounding off to that determines the amount of rounding off to be done based on the precision of the be done based on the precision of the measurementmeasurement

Using Significant Figures, Using Significant Figures, continuedcontinued

When you use measurements in calculations, When you use measurements in calculations, the answer is only as precise as the least the answer is only as precise as the least precise measurement used in the calculation.precise measurement used in the calculation.

The measurement with the fewest significant The measurement with the fewest significant figures determines the number of significant figures determines the number of significant figures that can be used in the answer.figures that can be used in the answer.

Section 3 Organizing DataChapter 1

Math SkillsMath SkillsSignificant Figures Significant Figures Calculate the volume of a Calculate the volume of a

room that is 3.125 m high, 4.25 m wide, and room that is 3.125 m high, 4.25 m wide, and 5.75 m long. Write the answer with the 5.75 m long. Write the answer with the correct number of significant figures.correct number of significant figures.

Section 3 Organizing DataChapter 1

Significant FiguresSignificant Figures

Section 3 Organizing DataChapter 1