STIV Physics Tm 2ndEdition

This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

PREFACE This book was designed and written for use by physics teachers regardless of the textbook they are using in the classroom. To make sure that this goal is achieved, we incorporated the following features in the book: 1. The teaching tips revolve around topics generally covered in a high school physics text, following the DepEd Curriculum Guide. 2. The discussions take into consideration the unifying themes of high school physics, namely: (a) physics as a basic science, (b) energy, (c) stability and equilibrium, (d) diversity and unity, (e) systems and interactions and (f) technology. 3. The book discusses Wiggins and Mctighe’s Understanding by Design (UbD) in the context of Physics, identifying the EUs and EQs per chapter and giving examples of performance tasks for assessment that denote understanding, find application in real life, and help develop thinking skills. To illustrate discussion points as well as sample instructional activities, we used VPHI’s Practical and Explorational Physics (Modular Approach) Second Edition and Laboratory Manual and Workbook in Physics by Padua and Crisostomo. And for additional information, we recommend internet resources, including i-learn.vibalpublishing.com. To our colleagues, good luck! THE AUTHORS

Science and Technology IV PRACTICAL AND EXPLORATIONAL PHYSICS Modular Approach Second Edition ISBN 978-971-07-2669-1 Copyright © 2010 by Vibal Publishing House, Inc. and Alicia L. Paduaa and Ricardo M. Crisostomo All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means—electronic or mechanical, including photocopying, recording or any information storage and retrieval system without permission in writing from the publisher and the authors. Artwork belongs solely to Vibal Publishing House, Inc. Published and printed by Vibal Publishing House, Inc. MANILA 1253 G. Araneta Ave., Quezon City CEBU Unit 202 Cebu Holdings Center, Cebu Business Park, Cardinal Rosales Ave., Cebu City DAVAO Kalamansi St., cor. 1st Ave., Juna Subdivision, Matina, Davao City ILOILO Unit 6, 144 M. H. del Pilar St., Molo, Iloilo City CAGAYAN DE ORO Unit 4, Bldg. A, Pride Rock Business Park, Gusa, Cagayan de Oro City Member: Philippine Educational Publishers’ Association; Book Development Association; Association of South East Asian Publishers; Graphic Arts Technical Foundation

ii This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

CONTENTS Partt ONE: TIME TABLE FOR THE COURSE ..................................................

2

Partt TWO: GENERAL COMMENTS ...............................................................

4

Partt THREE: SUGGESTIONS FOR EACH CHAPTER.................................... 10

UNIT I

Introduction to Physics .............................................................. 10

Chapter 1

What Is Physics? ..............................................................................................................

10

Chapter 2

How Are Physical Quantities Described? ...................................................................

14

UNIT II

MECHANICS ............................................................................... 18

Chapter 3

How Far and How Fast Do Objects Move? .................................................................

Chapter 4

How Does Force Cause a Change in Motion? ............................................................ 25

Chapter 5

How Is Equilibrium Achieved? .................................................................................... 33

18

Chapter 6

What Influences the Movements of Heavenly Bodies? ............................................. 38

Chapter 7

How Does Energy Produce Work? ............................................................................... 42

Chapter 8

What Happens When Objects Rotate? .........................................................................

47

Chapter 9

What Forces Influence Particle Movement in Matter? .............................................

51

UNIT III

Oscillations and Waves............................................................... 56

Chapter 10

How Do Particles Move in a Medium and Transfer Energy? ..................................

Chapter 11

How Is Sound Produced, Propagated and Perceived? .............................................. 60

56

UNIT IV

Thermodynamics ........................................................................ 65

Chapter 12

How Are Heat and Temperature Related? .................................................................. 65

Chapter 13

What Laws Govern the Transfer of Heat? ...................................................................

70

UNIT V

Electricity and Magnetism.......................................................... 74

Chapter 14

How Do Electric Charges That Are at Rest Interact? ................................................

74

Chapter 15

How Is Electricity Put into Use? ...................................................................................

78

Chapter 16

How Are Electricity and Magnetism Interrelated? ................................................... 84

Chapter 17

How Do Electronic Components Work? ..................................................................... 88

UNIT VI

Electromagnetic Waves and Optics .............................................. 91

Chapter 18

How Are Electronic Waves Used in Communication? .............................................

Chapter 19

What Is the Mystery Behind Light? .............................................................................

94

Chapter 20

How Are Images Reflected and Refracted by Mirrors and Lenses? .......................

98

91

UNIT VII

MODERN PHYSICS ....................................................................... 102

Chapter 21

What Is Relativity? .......................................................................................................... 102

Chapter 22

How Is Nuclear Physics Useful to Man? ..................................................................... 106

Chapter 23

What Are the Basic Building Blocks of the Universe? .............................................. 109

Appendix ....................................................................................................................... 112 Glossaryy .......................................................................................................................... 122

1 This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

Part ONE: TIMETABLE FOR THE COURSE A. NUMBER OF CLASS DAYS Unit/Chapter

UNITT

UNITT

UNITT

UNITT

UNITT

2

I

Introduction to Physics (10 days) Chapter 1 What Is Physics? Chapter 2 How Are Physical Quantities Described?

II Mechanics (75 days) Chapter 3 How Far and How Fast Do Objects Move? Chapter 4 How Does Force Cause a Change in Motion? Chapter 5 How Is Equilibrium Achieved? Chapter 6 What Influences the Movements of Heavenly Bodies? Chapter 7 How Does Energy Produce Work? Chapter 8 What Happens When Objects Rotate? Chapter 9 What Forces Influence Particle Movement in Matter?

III Oscillations and Waves (15 days) Chapter 10 How Do Particles Move in a Medium and Transfer Energy? Chapter 11 How Is Sound Produced, Propagated and Perceived?

IV Thermodynamics (10 days) Chapter 12 How Are Heat and Temperature Related? Chapter 13 What Laws Govern the Transfer of Heat?

V

Electricity and Magnetism (40 days) Chapter 14 How Do Electric Charges That Are at Rest Interact? Chapter 15 How Is Electricity Put into Use? Chapter 16 6 How Are Electricity and Magnetism Interrelated? Chapter 17 7 How Do Electronic Components Work?

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

Duration (number of days)

3-5 days 3-5 days

12-15 days 15-18 days 5-7 days 3-5 days 15-18 days 3-4 days 5-8 days

5-10 days 3-5 days

3-5 days 3-5 days

3-5 days 10-15 days 10-15 days 3-5 days

UNITT

UNITT

VI Electromagnetic Waves (15 days) Chapter 18 How Are Electromagnetic Waves Used in Communication? Chapter 19 What Is the Mystery Behind Light? Chapter 20 How Are Images Reflected and Refracted by Mirrors and Lenses?

3-5 days 3-5 days 3-5 days

VII Modern Physics (13 days) Chapter 21 What Is Relativity? Chapter 22 How Is Nuclear Physics Useful to Man? Chapter 23 What Are the Basic Building Blocks of the Universe?

3-5 days 3-5 days 2-3 days

B. SEMESTRAL AND QUARTERLY SCHEDULE

First Quarter

Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5

Second Quarter

Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11

Third Quarter

Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17

Fourth Quarter

Chapter 18 Chapter 19 Chapter 20 Chapter 21 Chapter 22 Chapter 23

First Semester

Second Semester

Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

3

Part TWO: GENERAL COMMENTS Following its mandate to improve the country’s curriculum for Basic Education in order to equip the youth with the skills and knowledge needed in this Information Age, the Department of Education (DepEd) deemed it wise to utilize the teaching-learning paradigm proposed by Grant Wiggins and Jay Mctighe (2002). The authors call it “Understanding by Design”, now popularly called UbD.

1. UNDERSTANDING BY DESIGN (UbD) Q1: In essence, what is UbD? It is a proposed design for a curriculum framework, a course program, a unit plan, a learning system and the like. It can simply be described as an instructional design. Q2: What are the major components of all instructional designs? All instructional designs, including UbD, have: (a) educational goals/objectives and content, (b) teaching-learning strategies, and (c) assessment. 1.1 Goals/Objectives and Content Educational psychologists group the general goals of education into three: a. Knowledge (cognitive goal) b. Skills, both cognitive and manipulative (behavioral goal) c. Attitudes (affective goal) Some educators express objectives as learning competencies. For lesson plans, some educators recommend that these be stated as behavioral objectives, since behavior is easiest to detect if the objectives have been attained. Content includes the main topics and major ideas per chapter. 1.2 Teaching Strategies and Techniques All instructional designs encourage teachers to use varied instructional activities that are relevant to the students’ daily life and cater to their learning styles and multiple intelligences. The strategies and techniques that teachers use vary depending on various factors—LEARNER factors (their characteristics, SES, readiness, etc.); LEARNING ENVIRONMENT factors (school facilities and equipment, books and other learning resources, etc.); and TEACHER factors (their academic background, trainings attended, teaching experience, etc.).

4

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

The teaching strategies also vary among the various academic disciplines. In science, for instance, found to be most effective are: (a) the inquiry approach and (b) hands-on learning or learning by doing, where the learner employs as many senses as possible in the learning process— touch, sight, hearing, smell. On the other hand, very effective in a skill subject are: (a) learning by doing and (b) drill/repetition. 1.3 Assessment Assessment is used to monitor learning, to find out if the students are achieving the objectives. It tells the teacher if the students understood what he/she taught them. Nontraditional or alternative tests, also called performance-based assessment or performance tasks, are characterized by the fact that the outputs or the answers to questions in the task are “constructed” by the students, borrowing the term from constructivism. The outputs of performance tasks are not graded the same way as the results of traditional tests. They are graded based on a set of criteria that is unique to each output. Thus, performance tasks are accompanied by rubrics.

2. IMPLEMENTATION STRATEGIES OF THE PROPOSED DESIGN Q3: In terms of the basic components of an instructional design, what are the contributions of UbD? The major contributions of UbD are in the areas of content and assessment. 2.1 Content Content is the structural base of the knowledge goal of education in school. a. UbD recommends that, from the start, the teacher should identify the main idea, or what UbD calls ‘big idea’ or ‘enduring understanding’ and what DepEd calls ‘essential understanding’ (EU). The idea is that, as far as content is concerned, the EU should serve as the focus of all the instructional activities in each chapter or unit or quarter. b. UbD also recommends that, to arrive at the EU, the teacher should initiate the discussion by means of a question, what UbD and DepEd call ‘essential questions’ (EQ). The answer to the EQ is the EU. Sometimes, several EQ are answered by one EU. And sometimes, one EQ is answered by several EU. 2.2 Assessment a. UbD recommends that, right after the identification of the EU, the teacher should think of the appropriate performance taskk that willTeacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

5

depict student understanding of the EU and supporting concept(s) and, at the same time, promote lifelong learning. The reason is that, since the teacher has a goal, he/she must have the appropriate tool, or instrument, to determine attainment of said goal. b. Once the students’ performance task has been identified, the teacher may now choose instructional activities that will help the students understand the EU and EQ and, at the same time, give them the knowledge and skills that will enable them to successfully accomplish the identified performance assessment.

3. UbD IN THE CONTEXT OF THE SCIENCE DISCIPLINE Q4: What are EU U and EQ to the science teacher? 3.1 In a science class, the EU U is usually called main idea or major idea or underlying science principle. And in this book, the EQ is called major area of inquiry. When a science teacher decides to write a lesson plan, the science principle or generalization to be taught is usually very clear in his/her mind right from the start. But the teacher does not teach the science principle per se. He/She uses science ideas or concepts to teach it. A science principle is actually a generalization from or synthesis of related concepts. But then again, the teacher does not teach a science concept per se. He/She uses facts (concrete things or experiences) to teach it. Let us illustrate this pedagogical strategy as follows: I

II

III

Principle

Concepts/Ideas

Facts/Experiences (Strategies)

There are many kinds of energy. There are many sources of energy. Energy can be changed from one form to another.

E.g., lab work field trips film showing demonstration

Energy is conserved.

Figure 1

Figure 1 shows that the sequence of steps in the teacher’s lesson plan is: I-II-III. But from the learners’ perspective, it is the reverse:

6

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

First: The students will probably be given a laboratory activity where they will be asked to observe how energy is transformed. Also, they will probably go on a field trip to an amusement park to observe how energy is transformed in the different rides. And they will probably be shown a film about the different sources of energy and how they are transformed to other forms. Second: After the activities that exposed them to different sources of energy and transformation of energy, the students are now in the position to say that: energy can be transformed from one form to another. Third: Finally, the students can make the generalization that: energy is conserved, it cannot be created nor destroyed. Thus, the sequence of steps (Figure 1) in the learner’s psyche is III-II-I. 3.2 To the science teacher, what are the essential features that should be reflected in his/her instructional design? The following questions should guide him/her in constructing the lesson plan: a. What are the science principles (EU) and supporting science concepts (EQ) that you would like your students to learn from the lesson? (This is essentially the CONTENT of the lesson.) b. What TEACHING STRATEGIES will you use so that the students will understand the content (EU and EQ) of the lesson? (‘Understanding’ here implies the ability of the learner to apply/ transfer what is learnt in school to situations in life.) c. How do you plan to test if the students understood the lesson? Or what do you want the students to do as evidence of understanding? (This ASSESSMENT is a performance task that should be evaluated on the basis of certain criteria. To this end, the Appendix of this book contains sample rubrics for different outputs: poster, model, foldables, etc.)

4. LABORATORY/FIELD ACTIVITIES VPHI has published a book entitled Laboratory Manual and Workbook in Physics. The authors prepared exercises based on the resources available in the community, the facilities and equipment present in the school, and other considerations like length of time entailed, expenses to be incurred, and security of the students.

Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

7

Needless to say, no physics class is expected to perform all exercises. The teacher has the final decision as to how many and which exercises his/her class will perform. In fact, the teachers are enjoined to feel free to modify the exercises according to the needs of the students and the limitations in the school setting.

5. INTEGRATION OF VALUES EDUCATION Perhaps the best guidelines with regard to values education are these: a. Model the values, attitudes and traits related to the topic or activity scheduled for the day. b. Take advantage of every opportunity in class to integrate desirable values and attitudes appropriate for the subject matter scheduled for discussion. Do not hesitate to give a spiritual orientation to the discussion, as long as the values/attitudes are indeed suited to the topic(s) at hand. c. Do not leave the matter of integration of values purely to chance. Do prepare for it. Be ready with teaching techniques and instructional materials for the purpose.

6. FRAMEWORK OF THE BOOK This book has three main parts: Part One is the timetable for the course; Part Two contains general comments; and Part Three contains suggestions for each chapter. These are followed by the Appendix. The suggestions for each chapter include the following sections. The introductory paragraph includes one or more of the pertinent unifying themes of physics listed below: • Physics as a basic science. How does everything in nature act in conformity with a law? • Energy. What is the unifying concept of all sciences? • Stability and Equilibrium. What is and what is not changing in nature? • Diversity and Unity. How are the forms of energy different or alike? • Systems and Interactions. How do the different systems interact with one another? Technically, as far as the general frameworkk of each chapter is concerned, the sections are supposed to be organized under the following headings:

I. CONTENTT (Stage 1 of the Proposed Instructional Design)

8

•

Underlying Science Principles, or Essential Understanding (EU)

•

Major Areas of Inquiry, or Essential Questions (EQ)

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

II. STUDENTS’ PERFORMANCE TASK(S) AS EVIDENCE OF UNDERSTANDING (Stage 2) III. COMMENTS AND SUGGESTIONS (STRATEGIES, etc.) (Stage 3) •

Exploring Students’ Prior Knowledge

•

Suggested Activities

But, if we make a paradigm shift from the chapter’s GENERAL FRAMEWORK to short LESSON PLANS, the instructional activities can be moved from section III to section II. And assessment can be moved from section II to section III, this time, as formative tests for daily monitoring of learning. The rest of the sections are the following:

IV. ANSWERS TO REVIEW W QUESTIONS IN THE TEXTBOOK V. CONCEPT MAP/OTHER GRAPHIC ORGANIZERS These sections, especially the subsections of item No. III (Comments and Suggestions), may be rearranged whenever deemed advisable. Finally, the Appendix contains sample scoring rubrics that you may want to use for rating the students’ performance tasks (item No. II). These sections, especially the subsections of item No. II, may be rearranged when deemed advisable.

7. INTERNET RESOURCES To facilitate student understanding of specific topics and to widen their perspective of that particular area of physics, the students may be encouraged to visit the websites suggested in the book Practical and Explorational Physics, Second Edition by Alicia L. Padua, and Ricardo M. Crisostomo.

Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

9

Part THREE: SUGGESTIONS FOR EACH CHAPTER UNITT

I INTRODUCTION TO PHYSICS

Unit I consists of two chapters: What Is Physics? (Chapter 1) and How Are Physical Quantities Described? (Chapter 2). The unit is about physics and its nature. It deals with the different branches of physics. It also deals with the major steps of the scientific method and how this has been applied by famous physicists, both local and foreign. Furthermore, it discusses the fundamental quantities, their representations, measurements, and derivations of mathematical relationships.

Chapterr

1 What Is Physics?

This chapter includes three modules. Physics: The Basic Science (Module 1), Nature’s Laws Are Mathematical and Simple (Module 2) and Career Opportunities that Await a Physicist (Module 3). Module 1 presents the relationship of physics with other branches of natural science. It also discusses how a problem can be solved using the Scientific Method. Furthermore, it explains how physics becomes the basis of technology that changes people’s way of living and thinking. Module 2 is about tools that are used in the study of the physical world. It also discusses how physical quantities are classified, measured, quantified, and related to one another. Module 3 presents famous Filipino and foreign physicists. It also discusses career opportunities that await a physicist.

I. CONTENTT Underlying Science Principles, or Essential Understanding (EU) 1. 2. 3. 4.

Physics principles are applicable in everyday life. Scientific theories are based on careful observations and measurements. Greatness of ideas starts from simple things. People’s way of thinking and living is greatly affected by their attitudes.

Major Areas of Inquiry, or Essential Question (EQ) 1. Why is physics considered a basic science? 2. How can the scientific method lead to discoveries and advances in science? 3. Why do we measure? 4. How will you measure a quantity with a reasonable degree of accuracy and precision?

10

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

5. Why are the concepts in physics described with mathematical formula? 6. How do physicists think and work? 7. How can gained knowledge, acquired skills and formed values lead to better opportunities in life?

II. STUDENT’S PERFORMANCE TASK AS EVIDENCE OF UNDERSTANDING Example: Give the students the following instruction. a. Prepare a plan for improving an existing technology. b. Design and construct a box with a square base of 100 cm2 using one used short folder and without any adhesive or binding material. Make sure that the box can hold grains or liquid. c. Make a “foldable” about a Filipino physicist that includes his/her picture, life, works, and contributions. Note: Use the appropriate rubric found in Appendix.

III. COMMENTS AND SUGGESTIONS A. Exploring Students’ Prior Knowledge Use “What I Know-What I Want to Know-What I learned” (K-W-L) Chart to elicit students’ prior knowledge on the nature of physics as a branch of science. B. Suggested Activities 1. Motivation: Begin by asking the students, “How will you compare science to a tree?” 2. Discuss the branches of science based on the output of the motivational activity. 3. Perform Exercise 1: Physics and Its Branches (VPHI Laboratory Manual and Workbook in Physics, p. 4). 4. Provide a real life problem that can be solved using the scientific method. 5. Perform Exercise 2: Scientific Method: (LMWP, p. 5). 6. Weblink: Ask the students to visit http://www.sossrilanka.com/uni/ sponge-bob-scientific-method-worksheet.html. 7. Panel Discussion: Select a number of students to be part of a panel discussion on “Impacts of Technology”. 8. Ask the students to make an estimate of the size of the room. Then, let them determine the area of the room using their body parts as units of measurement. 9. Lead the students in the discussion on the importance of measurement. Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

11

10. Perform Exercise 4: Using a Vernier Caliper (LMWP, pp. 8-9). 11. Weblink: Ask the students to visit http://www.aaastudy.com/mea69_ x6.htm#section2. 12. Provide the students with different sets of data that they could present graphically on a graphing paper or using EXCEL to determine the relationship that exists between the physical quantities. 13. Perform Exercise 5: The Physicist Way of Life (LMWP, pp. 10-13). 14. Lead the students in the discussion on local and foreign physicists and the career opportunities that await a physicist. 15. Let the students answer the last column of the K-W-L chart. 16. Ask the students to prepare a graphic organizer that will show their understanding of the concepts learned. 17. Enrichment Activity: Ask the students to interview Filipino physicists. 18. Use any of the following to assess students’ understanding. a. Seatwork (Chapter Review) b. Short quiz c. Portfolio d. Prompts e. Learning Logs

IV. ANSWERS TO REVIEW W QUESTIONS A. 1. d 2. b 3. a 4. d B. 1.

SF

SN

a.

3

1.43 × 102

b.

3

3.67 × 101

c.

4

2.009 × 103

d.

1

5 × 10–3

e.

4

3.5 × 103

2. a. 604 800 s

12

e. 2.16 × 10–2 m/s

b. 99 500 KHz

f.

2.5 × 1013 mm2

c. 300 L

g. 2.96 × 104 ft/s

d. 4.75 × 10–4 m3

h. 7.5 × 10–4 mm

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

3. a. direct square b. d = 4.9 t2 300

d. d = 122.5 m

Distance

c. t = 6.39 s

200

100

2

6

4

8

Time

V. GRAPHIC ORGANIZER: TREE DIAGRAM

Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

13

Chapterr

2 How Are Physical Quantities Described?

This chapter is composed of two modules: Identifying Scalars and Vectors (Module 4) and Adding Vectors (Module 5). Module 4 reviews the physical quantities and classifies these quantities as either scalar or vector. It also illustrates how to represent a vector quantity. Module 5 demonstrates how to add or combine two or more vectors into a single vector and how to find the perpendicular components of a single vector using graphical and analytical method.

I. CONTENT Underlying Science Principles, or Essential Understanding (EU) 1. A scalar quantity has magnitude only while a vector quantity has both magnitude and direction. 2. A vector quantity is represented by an arrow—the length of the arrow represents the magnitude and the arrowhead points the direction. 3. The resultant is the single vector that represents the sum of two or more vectors. 4. The equilibrant is the single vector that is equal in magnitude but opposite in direction to the resultant. 5. A single vector can be resolved into its perpendicular components. 6. Vectors can be combined or resolved using graphical or analytical method.

Major Areas of Inquiry, or Essential Question (EQ) 1. How can you say that an object is in equilibrium? 2. Into what type of forces can a singular force be resolved? 3. How many forces can be combined to a single force?

II. STUDENTS’ PERFORMANCE TASK AS EVIDENCE OF UNDERSTANDING Example: Give the students the following instruction. a. Prepare a vector art using ten vectors. b. Create at least five (5) vector problems on vector addition and at least five (5) on vector resolution. Note: Use the appropriate rubrics found in Appendix.

14

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

III. COMMENTS AND SUGGESTIONS A. Exploring Students’ Prior Knowledge 1. Given the following physical quantities, group them according to their common characteristics. acceleration mass displacement speed distance velocity force weight B. Suggested Activities 1. Discuss the difference between distance and displacement. 2. Identify quantities with directions (vectors) and without directions (scalars). 3. Answer Self-checkk (textbook, p. 31). 4. Illustrate how to represent the vector quantity graphically. 5. Answer Self-checkk (textbook, p. 32). 6. Perform Exercise 6: Vectors and Scalars (LMWP, pp. 14-15). 7. Illustrate how to do a vector addition using the graphical method. (See Examples 1-4, textbook, p. 33-34). 8. Answer Self-checkk (textbook, p. 35). 9. Review the Pythagorean Theorem and the Trigonometric Functions as an introduction to Vector Resolution. 10. Answer Self-checkk (textbook, p. 36). 11. Illustrate how to add vectors using the Analytical Method (See examples on pp. 37-39, textbook). 12. Answer Self-checkk (textbook, p. 39). 13. Perform Exercise 7: Who Will Win? (LMWP, pp. 16-17) 14. Use any of the following to assess student’s understanding. a. Seatwork (Chapter Review) b. Short quiz c. Board work

IV. ANSWERS TO REVIEW W QUESTIONS A. Multiple Choice 1. b 2. d 3. b

4. b 5. b

B. 1. 12 km E 8 km W 12 km – 8 km = 4 km E Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

15

N

12 km E

W

R= 4 km E

E

8 km W

S

2. 5 cm E 3 cm N 6 cm W N

6 cm W R

θ 3 cm N

W

E 5 cm E

S

1 3 θ = tan–1 (.33) θ = 18° W of N

R = (1 cm)2 + (3 cm)2

θ=

= 1 cm 2 + 9 cm 2 = 10 cm 2 R = 3.16 cm

25

N

3. 25 N 60°

Fy 60 θ Fx

16

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

Fx = F cos θ = 25 cos 60° Fx = 12.5 N ≈ 13 N

Fy = F sin θ = 25 sin 60° Fy = 21.65 N ≈ 22 N

4. 50 km N 30 km 20° N of W 50 km N 30 km 20° N of W

x

y

0

50

(30 cos 20°) (30 sin 20°) –28.19 10.26

Σ

–28.19

60.26

60.26 28.19 = 64.93° N of W

R = ( – 28.19 km)2 + (60.26 km)2

tan θ =

= 794.68 km 2 + 3631.27 km 2 = 4425.95 km 2 R = 66.53 km 5. 70 m 50° SE dx = 70 cos 50° = 45 m East

dy = 70 sin 50° = 53.62 m South ≈ 54 m South

V. GRAPHIC ORGANIZER: CONCEPT MAP

PHYSICAL QUANTITIES can be classified as

VECTORS

can be combined

SCALARS

GRAPHICALLY

ANALYTICALLY

using

HEAD-TAIL METHOD

POLYGON METHOD

Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

17

UNITT

II MECHANICS

Unit II consists of seven chapters: How Far and How Fast Do Objects Move? (Chapter 3), How Does Force Cause a Change in Motion? (Chapter 4), How Is Equilibrium Achieved? (Chapter 5), What Influences the Movements of Heavenly Bodies? (Chapter 6), How Does Energy Produce Work? (Chapter 7), What Happens When Objects Rotate? (Chapter 8) and What Forces Influence Particle Movement in Matter? (Chapter 9). This unit deals with subbranch of classical physics that is concerned with the forces acting on bodies whether at rest or in motion. It includes statics which focuses on the way in which forces combine with each other so as to produce equilibrium, kinematics which focuses on the motion of the body without regard to the cause of that motion and dynamics which focuses on the way in which force produces motion.

Chapterr

3 How Far and How Fast Do Objects Move?

This chapter includes three modules. Kinematics: Description of Motion (Module 6), Motion of Falling Objects (Module 7) and Projectile Motion (Module 8). Module 6 deals with the description of motion using graphs and kinematic equations. Module 7 discusses the motion of falling objects and the factors that affect their rate of fall. Module 8 deals with the motion of an object thrown with an initial velocity horizontally or at an angle.

I. CONTENT Underlying Science Principles, or Essential Understanding (EU) 1. 2. 3. 4. 5. 6.

Motion is relative. Acceleration can be positive or negative (deceleration). Motion problems can be broken into parts. Anything that goes up, goes down. When you reach the top, there is no way but to go down. Resistance affects output.

Major Areas of Inquiry, or Essential Question (EQ) 1. 2. 3. 4. 5.

18

When do you say that a body is in motion? How would you describe an accelerating object? What factors affect an object’s rate of fall? How will you compare free fall and projectile motion? How do you hit/attain the targets/goals that you set in your life? Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

II. STUDENTS’ PERFORMANCE TASK AS EVIDENCE OF UNDERSTANDING Ask the students to determine their reaction time or determine the height of a building using the concept of free fall. Note: Use the appropriate rubric found in Appendix.

III. COMMENTS AND SUGGESTIONS A. Exploring Students’ Prior Knowledge Identify whether the given situation illustrates a body in motion. 1. a car parked in a garage 2. a passenger inside a moving vehicle 3. a boy walking with his dog side by side 4. a passenger seated in a moving airplane 5. a ball rolling along the floor B. Suggested Activities 1. Motivation: Relate the students’ responses in part A above with their response to this question—What do objects in motion have in common? 2. Ask the students to show the difference between distance and displacement by walking from a specific starting point to a particular location inside the room. 3. Answer Self-check (textbook, p. 49). 4. Discuss speed and velocity. 5. Illustrate how to solve speed and velocity problems. 6. Guide the students in the derivation of the kinematic equations. (Refer to Table 6 on p. 51 textbook). 7. Answer Self-check (textbook, p. 52). 8. Ask the students to plot the given data and draw the graph. d (m)

10

20

30

40

50

t (s)

1

2

3

4

5

9. From the graph in No. 8, review how to determine the slope of a line. 10. Compare the slopes of the graph in Fig. 6.3 and Fig. 6.4 on page 52 of the textbook to show the difference between the motion of the object in the two graphs. 11. Use Fig. 6.5 to describe the different types of motion. 12. Perform Taskk (textbook, p. 53). 13. Answer Self-checkk (textbook, p. 53). 14. Perform Exercise 8: Changing Speed in the Laboratory Manual and Workbook in Physics (LMWP, pp. 26-27). Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

19

15. Perform Exercise 9: Falling Objects (LMWP, pp. 28-29). 16. Conduct a post lab-discussion and derive formulas for free fall from uniformly accelerated motion. 17. Illustrate how to solve free fall problems. 18. Answer Self-checkk (textbook, p. 58). 19. Perform Exercise 10: Beyond Free Fall: Throwing the Ball Upward (LMWP, p. 30). 20. Show video clips that exhibit terminal velocity and ask the students what will happen if the object does not attain terminal velocity. 21. Perform m Exercise 11: Comparing Free Fall and Projectilee (LMWP, p. 31 – 32). 22. Derive the formulas for horizontal projection. 23. Illustrate how to solve problems on horizontal projection. 24. Answer Self-check (textbook, p. 60). 25. Perform Exercise 12: Projectile Launched Horizontally (LMWP, pp. 33 -34). 26. Derive the formulas for projectiles launched at an angle. 27. Illustrate how to solve problems on projectiles launched at an angle. 28. Perform Exercise 13: Projectile Launched at an Angle (LMWP, p. 35). 29. Enrichment Activity: Determine the hang time of a basketball player using the equation on a projectile motion. 30. Use any of the following to assess students’ understanding. a. Seatwork (Chapter Review) b. Short quiz c. Board work 31. Ask the students to visit the suggested Weblinkk on p. 64 of the textbook.

IV. ANSWERS TO REVIEW W QUESTIONS A. 1. 2. 3. 4. 5.

20

d a and e b and h d c and f

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

B. 1.

a=2 a)

m s2

vi = 0

t = 10 s v f = v i + at ⎛ m⎞ = 0 + 2 2 (10 s) ⎝ s ⎠ v f = 20

b)

m s

t = 15 s 2

d = vi t +

at 2

=0+

=

⎛ m⎞ 2 (15 s) 2 ⎝ s2 ⎠ 2

⎛ m⎞ (225 s 2 ) 2 ⎝ s2 ⎠ 2

d = 225 m ≈ 220 m

c)

d = 500 m d = vi t +

at 2 2

2d = at 2 t=

2d a

=

2 (500 m) m 2

m

=

500 s 2

s2

t = 22.36 s ≈ 22 s

2. dy = 25 m

vi = 0

a) v f = v i 2 + 2 dg ⎛ m⎞ = 0 + 2 (25 m) 9.8 2 ⎝ s ⎠ m2 s2 m m v f = 22.14 ≈ 22 s s = 490

b) t =

vf – vi g

m –0 s = m 9.8 2 s t = 2.26 s ≈ 2.3 s 22.14

Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

21

3. d = 30 m a) t = =

=

v x = 12

m s

2d g m 2(30 m) m 9.8 2 s 60 s 2 9.8

= 6.12 s 2 t = 2.47 s ≈ 2.5 s b) R = v x t ⎛ m⎞ = 12 (2.47 s) s⎠ ⎝ R = 29.64 m ≈ 30 m c)

v f = 0 + gt y

⎛ m⎞ = 9.8 2 (2.47 s) ⎝ s ⎠ = 24.21

m s 2

⎛ m⎞ ⎛ m⎞ v f = 12 + 24.21 s⎠ s⎠ ⎝ ⎝

2

R

m2 m2 + 586.12 s2 s2 m m v f = 27.02 ≈ 27 s s m v i = 35 θ = 35° s v y = v i sin θ = 144

R

4.

⎛ m⎞ (sin 35º) = 35 s⎠ ⎝ ⎛ m⎞ = 35 (0.57) s⎠ ⎝ m v y = 19.95 s Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

a) R =

vi 2 sin 2 θ g 2

⎛ m⎞ 35 [sin 2(35°)] s⎠ ⎝ = g ⎛

m2 ⎞ (sin 70°) s2 ⎠ ⎝ = m 9.8 2 s (1225 m)(0.94) 1151.5 m = = 9.8 9.8 1225

= 117.5 m ≈ 120 m b) d y =

(v i sin θ) 2 2g

⎡⎛ m ⎞ ⎤ (sin 35°) ⎥ ⎢ 35 s ⎠ ⎣⎝ ⎦ = ⎛ m⎞ 2 9.8 2 ⎝ s ⎠ ⎡⎛ m ⎞ ⎤ (0.57) ⎥ ⎢ 35 s ⎠ ⎣⎝ ⎦ = m 19.6 2 s 398

2

2

m2

= 19.6

s2 m

s2 d y = 20.31 m ≈ 20 m

c)

tT =

2 vy g

⎛ m⎞ 2 19.95 s⎠ ⎝ = m 9.8 2 s m 39.9 s = m 9.8 2 s t T = 4.07 s ≈ 4.1 s Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

23

V. GRAPHIC ORGANIZER: CONCEPT MAP

46;065

JHUIL

VYR

^OPJOPZ LP[OLY

HJ[PUNVUHUVIQLJ[ V]LYHKPZWSHJLTLU[ WHYHSSLS[V[OL MVYJLPZKVPUN

-VYJL

2PUL[PJ ,ULYN` JOHUNLZ^P[O

THZZ ]LSVJP[`

46

7V[LU[PHS ,ULYN` PUJS\KLZ

LSHZ[PJ WV[LU[PHS LULYN`

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

NYH]P[H[PVUHS WV[LU[PHS LULYN`

Chapterr

8

What Happens When Objects Rotate?

This chapter includes three modules, (Module 24), Rotational Inertia (Module 25) and Angular Momentum and Its Conservation (Module 26). Module 24 shows how the distance, velocity and acceleration of an object in rotational motion can be measured. It also includes comparison of rotational and linear kinematic equations. Module 25 discusses how inertia applies to objects exhibiting rotational motion. Module 26 focuses on angular momentum of an object in rotational motion. It shows the similarity between linear and angular momentum. It also includes discussion on conservation of angular momentum and its application.

I. CONTENT Underlying Science Principles, or Essential Understanding (EU) 1. In the absence of an unbalanced external torque, the angular momentum of a system remains constant. 2. Decreases in rotational inertia lead to increases in rotational velocity such as in the spinning ice skater or diver and a planet orbiting the sun.

Major Areas of Inquiry, or Essential Question (EQ) 1. How can you describe rotational motion? 2. Why do bicycles and other similar objects remain upright when they are moving but not when they are stationary? 3. How do spinning objects (such as skates and discus) change their rotational velocities? 4. When is angular momentum conserved?

II. STUDENTS’ PERFORMANCE TASKS AS EVIDENCE OF UNDERSTANDING Examples: Give the students the following instructions. 1. Prepare demonstration activity that will explain how the location of an object’s mass with respect to its axis of rotation determines its rotational inertia. 2. Visit an amusement park/playground with a freely-rotating child’s merry go round. Take some time to observe some of the phenomena discussed in this chapter. Prepare a report that includes the time it takes for the merry-go-round to come to rest after you stop pushing it and discuss the steps on how you did it. Note: Use the appropriate rubric found in Appendix. Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

47

Note: If there is no merry-go-round available in the park, you may use the Lazy Susan of a round dining table or you may improvise with the use of any rotating disc.

III. COMMENTS AND SUGGESTIONS A. Exploring Students’ Prior Knowledge Ask the students to perform Exercise 33: Rotational Kinematics (LMWP, p. 66). B. Suggested Activities 1. Discuss Rotational Kinematics using the results of Exercise 33. 2. Derive the equations for Rotational Kinematics. 3. Illustrate how to solve problems on Rotational Kinematics. 4. Do Taskk (textbook, p. 155). 5. Answer Self-check (textbook, p. 155). 6. Demonstration: Have the students try to balance on a finger an upright long stick with a massive weight on one end. Try at first with the weight at the finger tip, then with the weight at the top. 7. Lead the demonstration activity to the concept that rotational inertia is greater for the stick when it is made to rotate with the massive part far from the pivot point than closer. Thus the farther the mass, the greater the rotational inertia; the more it resists a change in motion. 8. Answer Self-check (textbook, p. 156). 9. Perform Exercise 34: Rotational Inertia (LMWP, pp. 67-68). 10. Present Table 25 (Textbook, p. 158) Moments of Inertia of Selected Bodies with Mass m and show illustrative examples. 11. Answer Self-check (textbook, p. 157). 12. Discuss Angular Momentum by comparing it with linear momentum. Refer to Table 26 (textbook, p. 159). 13. Show how to solve problems on Angular Momentum. 14. Do Taskk (textbook, p. 160). 15. Answer Self-check (textbook, p. 160). 16. Perform Exercise 35: Conservation of Angular Momentum (LMWP, pp. 69-70). 17. Use any of the following to assess students’ understanding. a. Seat work (Chapter Review) b. Short quizzes c. Demonstrations

48

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

IV. ANSWERS TO REVIEW W QUESTIONS A. 1. 2. 3. 4. 5. B. 1.

c b a b a L = 25 kg • m2/s m = 4 kg r = 0.25 m 25 kg • m 2 / s 25 kg • m 2 / s L = 25 m/s = = mr (4 kg)(0.25 m) 1 kg • m

v=

2. m = 40 kg r=

0.5 m = 0.25 m 2

1 mr2 2 1 = (40 kg)(0.25 m)2 2 = (20 kg)(0.063 m2) I = 1.26 kg • m2 3. θ = (4 rev)(2π rad/rev) = 8π rad ωf2 = ωi2 + 2αθ I =

ωf 2 – ωi2 2θ 0 – (3 rad / s)2 = 2(8π rad)

α=

=

–9 rad 2 / s 2 50.24 rad

α = 0.18 rad/s2 4. α =

τ 48 N • m 48 N • m 2 / s 2 = = I 8 kg • m 2 8 kg • m 2

= 6 rad/s2 5. I1ω1 = I2ω2 ω2 =

I 1ω 1 ⎛ 3.6 kg • m 2 ⎞ = (1 rev / s) 2 I2 ⎝ 1.2 kg • m ⎠

ω2 = 3 rev/s Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

49

6.

t=2s ω i = 4990 rpm rev 6.28 1 min i × × i rev min 60 s ω i = 522.29 rad / s = 4990

ωf = 0 ωf – ωi t 0 – 522.29 rad / s = 2s

α=

α = – 261.14 rad / s 2

V. GRAPHIC ORGANIZER: CONCEPT MAP 96;(;065(305,9;0(

KLWLUKZVU

PZHSZV[LYTLK HZ

2NT

PZ[OL\UP[MVY

4VTLU[VM0ULY[PH

+PZ[YPI\[PVU VM[OLTHZZ VMHUVIQLJ[

T\S[PWSPLKI` HUN\SHY]LSVJP[`PZ

(UN\SHY 4VTLU[\T

HWWSPLZ[V

9V[H[PVUHS 4V[PVU Z\JOHZ

6YIP[HS 4V[PVU

:WPU 4V[PVU

50

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

Chapterr

9

What Forces Influence Particle Movement in Matter?

This chapter includes two modules: Properties of a Solid (Module 27) and Mechanics of Fluids (Module 28). Module 27 discusses the characteristics and properties of solids. Module 28 discusses fluid statics and fluid dynamics.

I. CONTENT Underlying Science Principles, or Essential Understanding (EU) 1. All matter on Earth generally exist in any of the states of matter (solid, liquid, gas, plasma). 2. The behavior of matter depends on its characteristics and properties. 3. Most types of matter you encounter every day are mixtures of two or more components.

Major Areas of Inquiry, or Essential Question (EQ) 1. 2. 3. 4. 5.

What happens to the density of an object when it is cut into smaller pieces? Force = Pressure? Which objects float? sink? Why do some materials cling to each other? How is pressure transmitted? increased? reduced?

II. STUDENTS’ PERFORMANCE TASKS AS EVIDENCE OF UNDERSTANDING Example: Give the students the following instructions. 1. Construct a boat using aluminum foil or clay that can carry the greatest number of marbles without sinking. 2. Prepare a video/power point presentation of the application of the principles learned in this chapter in actual situations. Provide the necessary explanations. 3. Construct a cartesian diver and explain how it works. Note: Use the appropriate rubric found in Appendix.

III. COMMENTS AND SUGGESTIONS A. Exploring Students’ Prior Knowledge Word Webbing: Write the word solid in the center of the board. Ask volunteers (around 10) to write a word that comes to their mind related to the word. Circle each word and draw a line to connect the words that relate to each other. Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

51

B. Suggested Activities 1. Use the clusters of words to discuss the properties of solids. 2. Answer Self-check (textbook, p. 165). 3. Perform Exercise 36: Hooke’s Law (LMWP, pp. 71-72). 4. Discuss Hooke’s Law. 5. Answer Self-check (textbook, p. 169). 6. Derive the equations for Modulus of Elasticity. 7. Show illustrative examples. 8. Recall with the students the concept of density. 9. Answer Self-check (textbook, p. 174). 10. Perform Exercise 37: Pressure (LMWP, p. 73). 11. Discuss the results of Exercise 37 and introduce liquid pressure. 12. Perform the activities in Do This (textbook, p. 174). 13. Derive the equations for pressure. 14. Show illustrative examples. 15. Answer Self-check (textbook, p. 176). 16. Show Pascal’s Principle in actual situations. Example: squeezing a tube of toothpaste. 17. Derive the equation for Pascal’s Principle. 18. Answer Self-check (textbook, p. 178). 19. Perform Exercise 38: Liquid Pressure (LMWP, p. 75). 20. Do POE (Predict-Observe-Explain) a. Fill a large clear container with water. b. Show two cans full of soft drink, one diet and one regular. c. Ask students to predict what happens if the can of diet soft drink is placed in the container. Ask them to observe and write their explanation. Do the same with the can of regular soft drink. 21. Discuss Buoyancy and Archimedes’ Principle using POE results. 22. Answer Self-check (textbook, p. 180). 23. Perform this activity. • Pour water into a glass until it is ¾ full. • Gently place a needle on the surface of the water. Try to make it float. • Do the same with paper clip and staple wire and other lightweight items. • Relate cause and effect. 24. Discuss surface tension using observations from the previous activity.

52

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

25. 26. 27. 28. 29. 30.

Answer Self-check (textbook, p. 182). Perform Exercise 40: Bernoulli’s Principle (LMWP, p. 77). Discuss Bernoulli’s Principle using the results of Exercise 40. Do the Taskk (textbook, p. 185). Answer Self-check (textbook, p. 185). Use any of the following to assess students’ understanding. a. Seatwork (Chapter Review) b. Short quizzes c. Journal Have students think of the effects of water’s high surface tension as applied in daily life. Describe the effect.

IV. ANSWERS TO REVIEW W QUESTIONS A. 1. 2. 3. 4. 5. B. 1.

d d c c b diameter = 1.0 mm = 1 × 10–3 m Lo = 2.0 m m = 5.0 kg ∆L = 1.2 mm = 1.2 × 10–3 m Y=

FLo (5.0 kg)(9.8 m / s 2 )(2.0 m) = A ΔL (3.14)(5 × 10 –4 m)2 (1.2 × 10 –3 m) =

98 J 9.42 × 10 –10 m 3

× 1011 N/m2 2. Fair = 50 N Fwater = 36 N mmetal =

Foil = 41 N

Fair 50 N = 5.10 kg = g 9.8 m / s 2

Fb(water) = ρwater gVmetal

Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

53

Vmetal = =

Fb( water ) ρwater g 14 N = 1.43 × 10–3 m3 (1 × 10 kg / m 3 )(9.8 m / s 2 ) 3

5.10 kg = 3.57 × 103 kg/m3 –3 3 1.43 × 10 m

ρmetal=

Fb(oil) = Fair – Fwater = 50 N – 41 N = 9 N Fb(oil) = ρoil gVmetal ρoil =

Fb(oil) g Vmetal

=

9N (9.8 m / s )(1.43 × 10 –3 m 3 ) 2

ρoil = 6.42 × 102 kg/m3 3. hwater = 20 cm hoil = 30 cm P = 0.70 × 103 kg/m3 a. P = ρghoil + Pa = (0.70 × 103 kg/m3)(9.8 m/s2)(0.30 m) + Pa = 2058 Pa + (1 × 105 Pa) = 102 058 Pa P = 1.02 × 105 Pa (surface) b. P = Pa + ρghoil + ρghwater = (1 × 105 Pa) + 2058 Pa + (1000 kg/m3)(9.8 m/s2)(0.2 m) = (1 × 105 Pa) + 2058 Pa + 1960 Pa = 104 018 Pa P = 1.04 × 105 Pa (bottom) 4. F2 = (1200 kg)(9.8 m/s2) = 11 760 N A1 = 12 cm2 A2 = 700 cm2 F1 = ? F F1 = 2 A1 A2 F1 = =

F2 A 1 A2 (11 760 N)(12 cm 2 ) 700 cm 2

F1 = 201.6 N

54

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

V. GRAPHIC ORGANIZER: CONCEPT MAP

-3VYR

;YHUZMLYYPUN/LH[

HYLNV]LYULKI`

-09:;3(>6-;/,946+@5(40*:

Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

73

UNITT

V ELECTRICITY AND MAGNETISM

The unit consists of four chapters: How Do Electric Charges That Are at Rest Interact? (Chapter 14), How Is Electricity Put into Use? (Chapter 15), How Are Electricity and Magnetism Interrelated? (Chapter 16) and How Do Electronic Components Work? (Chapter 17). This unit explains the phenomena of electricity and magnetism. It discusses their nature and relationships. It also discusses how electricity and magnetism are applied in electric power generation, production of motion and in electronics.

Chapterr

14 How Do Electric Charges That Are at Rest Interact?

This chapter includes two modules, Interaction of Electric Charges (Module 44) and Electric Fields (Module 45). Module 44 discusses the nature and transfer of electric charges. It also deals with Coulomb’s Law. Module 45 includes a discussion on nature’s characteristics of electric field.

I. CONTENT Underlying Science Principles, or Essential Understanding (EU) 1. 2. 3. 4. 5.

Electric fields provide the force that moves charged particles. Like charges repel, unlike charges attract. Different materials have different affinities for electrons. Electrostatic force is stronger than gravitational force. Charge is conserved.

Major Areas of Inquiry, or Essential Question (EQ) 1. How do objects acquire charge? 2. How is electrostatic force similar to and different from gravitational force? 3. How does the concept of a field eliminate the idea of action at a distance? 4. Can electric fields be shielded?

II. STUDENTS’ PERFORMANCE TASK AS EVIDENCE OF UNDERSTANDING Example: Give the students the following instruction. Choose one problem and one application of electrostatics. (Ex. Problems: sheets of paper stick together, cotton fibers attract dust) Application: electrostatics paint spraying, photocopying and laser printing)

74

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

Build a model or create a poster to show the solution to the problem and a procedure on how the application works. Note: Use the appropriate rubric found in Appendix.

III. COMMENTS AND SUGGESTIONS A. Exploring Students’ Prior Knowledge 1. Ask the students to agree or disagree on the following. a. Electricity was discovered by Benjamin Franklin. b. It is safer to stay inside a car than stand outside during a thunderstorm. c. A charged body has only one type of charge. d Friction is a necessary factor in charging an object. e. The human body is a conductor. 2. Ask the students to give examples of static charge. (Ex. clinging clothes, static charge experienced after walking across a floor and touching a doorknob.) 3. Discuss students’ responses and relate them to transfer of electric charge. 4. Perform Exercise 57: Interaction Between Charged Particles (LMWP, p. 111) and Exercise 58: Electrostatic Charges (LMWP, p. 112). 5. Demonstrate the use of an electroscope (if available) or use Fig 44.5 textbook, p. 252 and Fig. 44.6, p. 253 to show charging by conduction, induction and polarization. 6. Ask the students to classify the following materials and group them into conductors and insulators using POE a. alcohol g. paper b. aluminum foil h. plastic c. copper i. rubber j. salt d. cork e. glass k. water f. oil l. wood 7. Answer Self-check, k p. 254 of the textbook. 8. Recall Newton’s Laws of Universal Gravitation and compare with Coulomb’s Law. 9. Show how to solve problems applying Coulomb’s Law using Sample Problem on p. 255 of the textbook. 10. Answer Self-check on p. 256 of the textbook. 11. Discuss electric field strength using Fig. 45.2, p. 257 of the textbook.

Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

75

12. Show how to solve problems involving electric field strength using Sample Problem on p. 258 of the textbook. 13. Ask the students to describe the direction of the electric lines of force using Fig. 45.4, p. 259 of the textbook. 14. Answer Self-checkk on p. 261 of the textbook. 15. Use any of the following to assess students’ understanding. a. Seatwork (Chapter Review) b. Short quizzes c. Surf the internet to find out the effects of static charge on your daily life and what you can do to minimize these effects. 16. Have the students visit the suggested Weblinkk on p. 262.

IV. ANSWERS TO REVIEW W QUESTIONS A. Multiple Choice 1. c 2. d 3. b 4. d 5. c B. Essay; Problem Solving 1. The charges that make up Q will spread out over the object’s surface. 2. No, two objects need not be charged for them to attract each other electrically. Yes, two objects have to be charged for them to repel each other electrically. Q2 = 2 × 10–7 C 3. Q1 = 5 × 10–7 C F = 100 N kQ 1 Q 2 F (9 × 109 Nm 2 / C2 )(5 × 10 –7 C)(2 × 10 –7 C) 100 N –3 d = 3 × 10 m 4. F1 = 9.3 × 10–4 N d1 = 20 cm = 0.2 m d2 = 4.5 cm = 0.045 m d3 = 86 cm = 0.86 m F2 = ? F3 = ? d=

76

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

F1 d1

2

=

2

F2 d2 2 = =

F1d 2 2 d1 2 (9.3 × 10 – 4 N)(4.5 cm)2 (20 cm)2

F2 = 4.71 × 10–5 N b. F3 =

F1d 2 2 d1 2

(9.3 × 10 – 4 N)(86 cm)2 = (20 cm)2

F3 = 1.72 × 10–2 N 5. The two forces (i.e., the gravitational attraction between two protons and their electric repulsion) are never equal.

V. GRAPHIC ORGANIZER: C0NCEPT MAP :;(;0*,3,*;90*0;@

PU]VS]LZ

9LWLS

,SLJ[YVZJVWL

KL[LJ[Z[OL WYLZLUJLVM

,SLJ[YPJ*OHYNLZ

JH\ZLVIQLJ[Z [V

OHZ[^VVWWVZP[L [`WLZ^OPJOHYL

7VZP[P]L

([[YHJ[

5LNH[P]L

Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

77

Chapterr

15 How Is Electricity Put Into Use?

This chapter includes three modules: Electrical Quantities and Units (Module 46), Ohm’s Law (Module 47) and Multiple-Load Circuits (Module 48). Module 46 introduces certain quantities and units in describing electric circuits. Module 47 presents applications of Ohm’s Law and the devices that are used to relate and measure the different quantities involved. Module 48 discusses the different types of circuit connections and their applications. It also includes a discussion on how to use electricity safely.

I. CONTENT Underlying Science Principles, or Essential Understanding (EU) 1. Electric circuits and electric current are central to understanding how simple electrical devices work. 2. Materials have the property of opposing an electric current. 3. There is a relationship among voltage, current and resistance given in Ohm’s law. 4. Current carries energy and does work.

Major Areas of Inquiry, or Essential Question (EQ) 1. 2. 3. 4.

Why does a bulb light? What is the relationship between current and voltage in a simple circuit? When a battery dies, does it run out of charge? Why are Christmas lights connected in series but houselights are connected in parallel? 5. Is electric energy the same as electric power? Explain. 6. What do we pay for, energy or power? 7. What safety measures are to be considered in using electricity?

II. STUDENTS’ PERFORMANCE TASK AS EVIDENCE OF UNDERSTANDING Example: Give the students the following instructions. 1. Make a survey of your electric energy consumption for the past three consecutive months. 2. Identify which devices consume more electric energy. 3. Propose an action plan on how to reduce your electrical energy consumption. 4. Discuss the plan with the other members of your family and explain how the plan will work. 5. Find out the results after two months. Note: Use the appropriate rubric found in Appendix.

78

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

III. COMMENTS AND SUGGESTIONS A. Exploring Students’ Prior Knowledge Pose the question: Give instances when electricity can be dangerous to you. (Example: handling a wet hair dryer, pulling appliances by their flex) B. Suggested Activities 1. P-O-E a. Show the diagram below and ask students to predict which setup will make the bulb light.

A

2. 3.

4. 5. 6.

7.

B

C

D

E

F

G

b. Ask the students to explain their answers. c. Provide materials (bulb, battery, copper wire) and let students verify their predictions through observations. d. Ask the students to explain the result. Introduce electric circuit and the quantities needed in describing an electric circuit. Use Table 46.1 p. 266 of the textbook to discuss the factors that affect resistance (R) to length (), cross-sectional area (A) and resistivity (ρ) ρ given by R = A Show how to solve problems involving factors affecting resistance using Sample Problems on p. 267 of the textbook. Answer Self-check, k p. 267 of the textbook. Using activity in No. 1 (P-O-E), ask the students to identify the parts of an electric circuit. Let them illustrate the circuit using a schematic diagram. Refer to Table 47.1 p. 268 of the textbook for symbols used in schematic diagram. Let students make an analogy between electric circuit and the flow of water in a pipe by asking them to match the terms in Column A (water-flow system) with Column B (electric circuit) A

B

Water-flow system

Electric Circuit

water

battery

pump

bulb

pipes

charge

narrow pipe

switch

valve

wires Teacher’s Manual

This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

79

Ask the students to explain their analogy. 8. Perform Exercise 62: Ohm’s Law (LMWP, pp. 117-118) to determine the relationship between current and voltage and between current and resistance. 9. Show how to solve problems by applying Ohm’s law using the Sample Problems on p. 269 of the textbook. 10. Derive with the students the formula for power and electrical energy. 11. Guide the students in distinguishing between energy and power by using a sample electricity bill shown in Table 47.2, p. 271. 12. Ask the students to share what they do at home to save electricity. 13. Answer Self-check, k p. 272 of the textbook. 14. Show the students actual set-ups of series and parallel circuit connections. Let them compare the two connections. 15. Show how to solve problems involving circuit connections using these circuit connections. b. parallel a. series

R T = 51

R 2 = 51

Emf = 3V

Emf = 3V

Find: RT = 10 Ω IT = 0.3 A V1 = 1.5 V V2 = 1.5 V I1 = 0.3 A I2 = 0.3 A

RT = 51

R 2 = 51

Find: RT = 2.5 Ω IT = 1.2 A V1 = 3 V V2 = 3 V I1 = 0.6 A I2 = 0.6 A

16. Show how to solve problems involving simple network connections using Sample Problems on pp. 274-275 of the textbook. 17. Answer Self-checkk on p. 277 of the textbook. 18. Ask the students to study Table 48 on p. 276 of the textbook to determine the electric shock hazards at different values of current. 19. Discuss with the students how electricity can both be a friend and a foe. Let the students share how car accidents related to electricity be prevented.

80

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

20. Use any of the following to assess students’ understanding. a. Seatwork (Chapter Review) b. Short quizzes c. Write a report on why various devices are wired in parallel. (Example: Ignition, head lights, tail lights, CD player) Estimate the combined resistance if another load will be added.

IV. ANSWERS TO REVIEW W QUESTIONS A. Multiple Choice 1. a 2. b 3. d 4. a 5. c B. Problem Solving 1. R = 10.4 Ω V = 220 V V 220 V = R 10.4 Ω I = 21.15 A I=

2. P = 320 W V = 110 V I=

P 320 W = 2.91 A = V 110 V

3. R1 = 4 Ω R2 = 8 Ω R3 = 12 Ω VT = 24 V a. RT = R1 + R2 + R3 = 4 Ω + 8 Ω + 12 Ω RT = 24 Ω b. IT =

VT 24 V =1A = R T 24 Ω

c. IT = I1 = I2 = I3 = 1 A

Teacher’s Manual This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

81

4. R1 = 18 Ω R2 = 9 Ω R3 = 6 Ω VT =12 V 1 1 1 1 = + + R1 R2 R3 RT

a.

1 1 1 + + 18 Ω 9 Ω 6 Ω 1 = 3Ω =

RT = 3 Ω b. IT = 4 A c. I1 = 0.67 A I2 = 1.33 A I3 = 2 A d. VT = V1 = V2= V3 = 12 V 5. R1 = 3 Ω R5 = 4 Ω R2 = 3 Ω R6 = 2 Ω R3 = 6 Ω R7 = 2 Ω R4 = 6 Ω RT = ? 1 R3 – 4

=

1 1 2 + = 6Ω 6Ω 6Ω

R3 – 4 = 3 Ω 1 R5 – 6

=

R5 – 6 =

1 1 3 + = 4Ω 2Ω 4Ω 4Ω 3

Series: R2 and R3–4 R2–3–4 = 3 Ω + 3 Ω =6Ω Series: R5–6 and R7 6Ω +2Ω 3 10 Ω = 3

R5–6–7 =

82

Practical and Explorational Physics This Teacher's Manual is intended only for teachers who use a Vibal CTLP. © Copyright 2010 by Vibal Publishing House, Inc. NOT FOR SALE.

Parallel:

R2–3–4 and R5–6–7 =

1 3 5+9 14 + = = 6 Ω 10 Ω 30 Ω 30 Ω

R2–3–4–5–6–7 =

30 Ω 15 Ω = 14 7

RT = R1 + R2–3–4–5–6–7 =3Ω+ RT =

15 Ω 7

36 Ω 7

V. GRAPHIC ORGANIZER: CONCEPT MAP :V\YJL IHZPJHSS` PUJS\KLZ

,3,*;90**09*